Patent blue interferes with the measurement of lipemia index in a patient with sentinel lymph node.

Lipids interfere with absorbance measurements conducted using colorimetric methods. To monitor lipemia, some systems measure absorbance using an analyzer. This report describes a novel case of interference with the lipemia index without lipemia. A 64-year-old woman with giant basal cell carcinoma underwent resection and sentinel lymph node biopsy. The patient had been subcutaneously injected with patent blue during sentinel lymph node resection. After surgery, her serum and urine were yellow-green, and the lipemia index, calculated by measuring absorbance at 658 nm (main wavelength) and 694 nm (secondary wavelength) using a JCA-BM8040 chemistry analyzer, was high. The absorbance spectrum of the patient's serum and patent blue solution were compared to determine the cause of the high lipemia index. The patient's serum and the patent blue solution showed absorption at wavelengths between 540 and 698 nm. Moreover, the absorbance was concentration-dependent for patent blue. These results thus indicated that the patient's serum contained patent blue. Here, we report a case wherein patent blue affected the lipemia index. Thus, it must be noted that patent blue injection may yield inaccurate results when evaluating lipemia index.

Development of a plasma maltose assay method as a screening test for upper gastrointestinal disorders.

BACKGROUND AND OBJECTIVE: The disaccharide loading test is a method to assess gastric mucosal damage. Since Trelan-G75, which is used for the sugar tolerance test, contains disaccharide maltose, if maltose is detected at a high sensitivity in the sample blood used in the sugar tolerance test, screening for upper gastrointestinal mucosal damage can be made simultaneously with the sugar tolerance test for the diagnosis of diabetes. METHODS: Glucose-6-phosphate is generated by treating maltose with maltose phosphorylase, ß-phosphoglucomutase, and glucose-1,6-bisphosphate. Then, change in the absorbance at 405 nm is measured by the enzymatic cycling method using Thio-NADP, ß-NADPH, and Glucose-6-phosphate dehydrogenase. After evaluating the optimal condition for this method, it is mounted on an automatic biochemical analyzer, and samples after the sugar tolerance test were assayed. RESULTS: Regarding the performance of this method, the repeatability was 10-50 µmol/L with a CV of ≤1.1%. Concerning the assay range, a curve passing the origin with a range of linearity up to 120 µmol/L was obtained. No effect of dyes or sugars in the blood was noted. As a result of application to patients with gastric mucosal disorders (those who had a health checkup), significant differences were observed depending on the stage of atrophic gastritis. DISCUSSION: This method has a high sensitivity and a high precision and can be used for high-speed analysis on an automatic analyzer. It has the potential to be used as a screening test for gastric mucosal damage.

Combinational antibody detection approach increases the clinical validity of colorectal cancer screening.

BACKGROUND: At different stages of the disease, biomarkers can help to determine disease progression and recurrence and provide a personalized indicator of therapeutic effectiveness. The serological identification of antigens by recombinant cDNA expression cloning (SEREX) has identified five SEREX antigens. RESULTS: Compared with healthy donors, anti-FIRΔexon2 and anti-SOHLH antibodies (Abs) in the sera of patients with colorectal cancer (CRC) were markedly higher. Furthermore, no correlation was noted between five SEREX antigens and the three tumor markers (CEA, CA19-9, and anti-p53 Abs), indicating that anti-FIRΔexon2 Abs are an independent candidate marker for patients with CRC. Generally, the levels of anti-FIRΔexon2 Abs combined with clinically available tumor markers were determined to be significantly higher compared with CEA, CA19-9. Moreover, in early-stage CRC, the levels of anti-FIRΔexon2 Abs combined with existing tumor markers were higher than those of CEA, CA19-9. CONCLUSION: Due to the highly heterogeneous nature of CRC, a single tumor marker is unlikely to become a standalone diagnostic test due to its commonly insufficient sensitivity and/or specificity. Using a combination antibody detection approach of tumor markers for CRC diagnosis has the potential to be an effective approach. Therefore, the use of serum protein biomarker candidates holds promise for the development of inexpensive, noninvasive, and inexpensive tests for the detection of CRC.

UTX inactivation in germinal center B cells promotes the development of multiple myeloma with extramedullary disease.

UTX/KDM6A, a histone H3K27 demethylase and a key component of the COMPASS complex, is frequently lost or mutated in cancer; however, its tumor suppressor function remains largely uncharacterized in multiple myeloma (MM). Here, we show that the conditional deletion of the X-linked Utx in germinal center (GC) derived cells collaborates with the activating BrafV600E mutation and promotes induction of lethal GC/post-GC B cell malignancies with MM-like plasma cell neoplasms being the most frequent. Mice that developed MM-like neoplasms showed expansion of clonal plasma cells in the bone marrow and extramedullary organs, serum M proteins, and anemia. Add-back of either wild-type UTX or a series of mutants revealed that cIDR domain, that forms phase-separated liquid condensates, is largely responsible for the catalytic activity-independent tumor suppressor function of UTX in MM cells. Utx loss in concert with BrafV600E only slightly induced MM-like profiles of transcriptome, chromatin accessibility, and H3K27 acetylation, however, it allowed plasma cells to gradually undergo full transformation through activation of transcriptional networks specific to MM that induce high levels of Myc expression. Our results reveal a tumor suppressor function of UTX in MM and implicate its insufficiency in the transcriptional reprogramming of plasma cells in the pathogenesis of MM.

Frequencies of Anti-Troponin I vs Anti-Troponin T Autoantibodies and Degrees of Interference on Troponin Assays.

OBJECTIVE: Presence of autoantibodies against troponin I (cTnI) or T (cTnT) has been reported to interfere with troponin assays. However, the extent of the interference with the measurement has not been explored sufficiently. The aims of this study were to examine the frequencies of autoantibodies against troponin I and troponin T and how much these antibodies would affect the measurement. METHODS: The study comprised 52 subjects who visited Hokkaido University Hospital with suspected ischemic heart diseases. To evaluate the presence of autoantibodies, we calculated the recoveries of cTnI or cTnT after immunoglobulin G depletion, and the distributions of peaks reactive with cTnI or cTnT by high-performance liquid chromatography were examined. RESULTS: Autoantibodies against cTnI and cTnT were identified in 8 subjects (15.4%) and 1 subject (1.9%), respectively. Although the greatest difference between cTnI and cTnT was 32-fold, the distributions of cTnI-to-cTnT ratios in groups with and without anti-cTnI were not statistically different. CONCLUSION: Autoantibodies against cTnI were more frequent by several fold than those against cTnT. Their presence did not significantly expand the discrepancy between cTnI and cTnT assays.

IgG4-IgE complex interferes with measurement of IgE concentration.

BACKGROUND AND AIMS: Patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD) have elevated immunoglobulin E (IgE) concentration compared to that in healthy individuals, which suggests the occurrence of IgE-mediated allergic reactions. We have previously shown that IgG4 and IgE form a complex in some patients with IgG4-RD. However, it is currently unknown whether and how the presence of the IgG4-IgE complex affects IgE concentration measurements by different assays. MATERIALS AND METHODS: Twenty patients with confirmed presence or absence of IgG4-IgE complex were evaluated. We compared IgE concentrations measured by ST AIA-PACK IgE II (AIA-PACK), Elecsys IgE II Immunoassay (Elecsys), and Iatroace IgE (Iatroace) and evaluated to what extent the IgG4-IgE complex interfered with these measurements. RESULTS: In patients with the IgG4-IgE complex, IgE concentrations measured using Iatroace were significantly lower than those measured using Elecsys and tended to be lower than those measured using AIA-PACK. IgE concentrations determined by Iatroace were significantly different in patients with and without the IgG4-IgE complex, whereas no significant differences between these groups were detected when IgE concentrations were measured by AIA-PACK or Elecsys. CONCLUSION: The formation of the IgG4-IgE complex underestimates measured IgE concentrations depending on the method used. Therefore, caution should be exercised when selecting a specific IgE assay for patients with IgG4-RD.

IgG4-IgE complex in patients with IgG4-related disease.

BACKGROUND: IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory disease characterized by high IgE levels; however, the physiological significance of elevated IgE levels in patients with IgG4-RD is unclear. Previously, we reported the formation of IgG4-IgE complex in IgG4-RD patients with elevated IgE levels. In this study, we examined the frequency of this complex formation and its relationship with the clinical features in IgG4-RD patients. METHODS: The IgG4-IgE complex was evaluated in 33 and 17 patients with and without IgG4-RD, respectively. The IgG4-IgE complex was evaluated by performing the immunoadsorption of IgG4 using anti-IgG4 antibody-conjugated matrices. RESULTS: The frequency of IgG4-IgE complex formation in patients with IgG4-RD was significantly higher than that in those without IgG4-RD (21.2% vs. 0%). No significant differences were observed between the groups in terms of clinical characteristics and laboratory data. However, the IgG4-IgE complex-positive group had a significantly higher frequency of pancreatic lesions (85.7% vs. 42.3%) and a significantly lower rate of retroperitoneal fiber/periarterial lesions (0% vs. 38.5%) than the IgG4-IgE complex-negative group. CONCLUSION: The IgG4-IgE complex was found only in patients with IgG4-RD which may provide some clues to the pathogenesis and etiology of IgG4-RD.

IgG4-IgE complex in a patient with IgG4-related disease.

BACKGROUND: IgE concentrations are occasionally elevated in patients with IgG4-related disease (IgG4-RD). In this report, we describe a novel case of IgG4-RD in which IgE concentrations were discordant between measuring reagents. CASE: An 81-year-old man was diagnosed with IgG4-RD and histological autoimmune pancreatitis, which ensued without treatment. The IgE concentrations measured using Elecsys IgE II Immunoassay and Iatroace IgE were 1287.0 IU/mL and 60.9 IU/mL, respectively. IgG4 concentration was 675 mg/dL. METHODS: To identify IgG and IgG4 directly bound to IgE, purification using protein G and anti-IgG4 antibody-conjugated matrixes and size-exclusion high-performance liquid chromatography (HPLC) were performed. RESULTS: In purification analysis, the IgE concentration of the flow-through and bound fractions were 6.8 IU/mL (10.8%) and 56.2 IU/mL (89.2%) for IgG purification and 6.8 IU/mL (12.2%) and 49.0 IU/mL (87.8%) for IgG4 purification. IgE was eluted as a single peak (640 kDa) using size-exclusion HPLC. In the elution pattern of IgG4, a minor peak (640 kDa) and a major peak (170 kDa) were observed. These results indicate that IgG4 binds to IgE and forms a complex, resulting in a discrepancy between reagents. CONCLUSIONS: In this report, we present an IgG4-IgE complex in a patient with IgG4-RD, which affected the discrepancy in IgE concentrations between IgE reagents. This report points to the significance of increased IgE production in IgG4-RD.

Anti-FIRΔexon2 autoantibody as a novel indicator for better overall survival in gastric cancer.

There is no clinically available biomarker for efficiently indicating the overall survival or therapy response of gastric cancer (GC). The autoantibodies (Abs) in the sera of anti-far-upstream element-binding protein-interacting repressor-lacking exon2 (FIRΔexon2), anti-sorting nexin 15, and anti-spermatogenesis and oogenesis-specific basic helix-loop-helix 1 were markedly higher in GC patients than in healthy donors (HDs). These Abs were identified by large-scale serological identification of antigens by recombinant cDNA expression cloning screenings and their expression levels were evaluated by amplified luminescence proximity homogeneous assay. In particular, compared with age-matched HDs, the level of anti-FIRΔexon2 Abs in GC patients was significantly higher (P < .001). The Spearman's rank correlation analysis between anti-FIRΔexon2 Abs and clinically available tumor markers such as carcinoembryonic antigen (CEA) was statistically insignificant, indicating that FIRΔexon2 Abs is an independent biomarker. We performed receiver-operating curve analysis to evaluate the anti-FIRΔexon2 Ab as a candidate biomarker with CEA and carbohydrate antigen 19-9 (CA19-9). The overall survival of GC patients with high anti-FIRΔexon2 Abs titer was significantly favorable (P = .04) than that of GC patients who were below detection level of anti-FIRΔexon2 Abs. However, clinical stages were not apparently correlated with the levels of anti-FIRΔexon2 Ab, CEA, and CA19-9. In conclusion, anti-FIRΔexon2 Abs detected in GC patients is a potential biomarker for monitoring a better prognosis. Hence, anti-FIRΔexon2 Abs is a promising biomarker for indicating better overall survival of gastric cancer patients.

A highly sensitive and rapid enzymatic method using a biochemical automated analyzer to detect inorganic pyrophosphate generated by nucleic acid sequence-based amplification.

BACKGROUND AND AIMS: Polymerase chain reaction-based techniques require expensive equipment for fluorescence detection of the products. However, the measurement of inorganic pyrophosphate (PPi) released during DNA synthesis can be used to quantify target genes without such equipment. Here, we devised a high-sensitivity enzymatic assay for detection of PPi. MATERIALS AND METHODS: In our assay method, PPi was converted to hypoxanthine by hypoxanthine phosphoribosyl transferase. Xanthine dehydrogenase converted the hypoxanthine to uric acid and yielded two molecules of NADH, which in turn reduced Fe3+ to Fe2+ (mediated by 1-methoxy-5-ethylphenazinium ethylsulfate). 2-Nitroso-5-(N-propyl-N-sulfopropylamino) phenol chelated the Fe2+, which resulted in an intensely colored product that could be measured using a biochemical automated analyzer. RESULTS: The assay was able to detect PPi within 10 min. It was linear between 0 and 10 µmol/L PPi, and intra-run and inter-run coefficients of variation were 1%-2%. Other validation tests with a biochemical automated analyzer were satisfactory. The assay could potentially be used to directly quantify samples after isothermal nucleic acid sequence-based amplification of a target gene. CONCLUSION: The method developed here for detection of PPi can be used to measure nucleic acid biomarkers in biological samples in clinical practice using a high-throughput biochemical automated analyzer.

Determination of serum carbohydrate-deficient transferrin by a nephelometric immunoassay for differential diagnosis of alcoholic and non-alcoholic liver diseases.

BACKGROUND: Carbohydrate-deficient transferrin is a biological marker of excessive drinking. The aim of this study was to evaluate the diagnostic value of a direct nephelometric immunoassay for the differential diagnosis of alcoholic and non-alcoholic liver diseases in comparison with gamma glutamyl transferase. METHODS: Serum samples were obtained from 305 subjects, including 122 patients with alcoholic and 102 cases with non-alcoholic liver diseases. Serum levels of carbohydrate-deficient transferrin were expressed as a percentage of total transferrin. RESULTS: Serum % carbohydrate-deficient transferrin levels were significantly higher in patients with alcoholic than with non-alcoholic liver diseases. Carbohydrate-deficient transferrin had better specificity than gamma glutamyl transferase to differentiate between alcoholic and non-alcoholic liver diseases.There were 8 alcoholic liver disease patients with normal gamma glutamyl transferase levels, and carbohydrate-deficient transferrin was significantly elevated in 6 of them. On the other hand, there were 25 non-alcoholic liver disease patients with elevated gamma glutamyl transferase levels; their carbohydrate-deficient transferrin levels were within the reference intervals in all cases. CONCLUSION: This simple carbohydrate-deficient transferrin immunoassay is useful to detect so-called gamma glutamyl transferase non-responding drinkers and also to exclude the possible role of excessive drinking in apparently non-alcoholic liver diseases. A large-scale prospective study is needed to further confirm the diagnostic utility of carbohydrate-deficient transferrin.

Development of a simple indocyanine green measurement method using an automated biochemical analyser.

Background The indocyanine green retention rate is important for assessing the severity of liver disorders. In the conventional method, blood needs to be collected twice. In the present study, we developed an automated indocyanine green method that does not require blood sampling before intravenous indocyanine green injections and is applicable to an automated biochemical analyser. Methods The serum samples of 471 patients collected before and after intravenous indocyanine green injections and submitted to the clinical laboratory of our hospital were used as samples. The standard procedure established by the Japan Society of Hepatology was used as the standard method. In the automated indocyanine green method, serum collected after an intravenous indocyanine green injection was mixed with the saline reagent containing a surfactant, and the indocyanine green concentration was measured at a dominant wavelength of 805 nm and a complementary wavelength of 884 nm. Results The coefficient of variations of the within- and between-run reproducibilities of this method were 2% or lower, and dilution linearity passing the origin was noted up to 10 mg/L indocyanine green. The reagent was stable for four weeks or longer. Haemoglobin, bilirubin and chyle had no impact on the results obtained. The correlation coefficient between the standard method (x) and this method (y) was r=0.995; however, slight divergence was noted in turbid samples. Conclusion Divergence in turbid samples may have corresponded to false negativity with the standard procedure. Our method may be highly practical because blood sampling before indocyanine green loading is unnecessary and measurements are simple.

Fractionation of gamma-glutamyltransferase in patients with nonalcoholic fatty liver disease and alcoholic liver disease.

AIM: To assess how serum gamma-glutamyltransferase (GGT) fractions vary in patients with alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD). METHODS: Serum samples were obtained from 14 patients with biopsy-proven alcoholic liver diseases and 9 patients with biopsy proven non-alcoholic fatty liver disease. In addition to these biopsy-proven cases, 16 obese (body mass index > 25) patients without any history of alcohol consumption but with a fatty liver on ultrasound examination and with elevated GGT were included for an additional analysis. Serum GGT fractionation was conducted by high-performance gel filtration liquid chromatography and was separated into the four fractions, big-GGT, medium-GGT, small-GGT (s-GGT), and free-GGT (f-GGT). RESULTS: The results were expressed as a ratio of each fraction including the total GGT (t-GGT). The s-GGT/t-GGT ratios were lowest for the control group and highest for the ALD group. The differences between the control and NAFLD groups and also between the NAFLD and ALD groups were statistically significant. In contrast, the f-GGT/t-GGT ratios were highest in the control group and lowest in the ALD group, with the differences being statistically significant. As a result, the s-GGT/f-GGT ratios were markedly increased in the NAFLD group as compared with the control group. The increase of the s-GGT/t-GGT ratios, the decrease of the f-GGT/t-GGT ratios, and the increase of s-GGT/F-GGT ratios as compared with the control group subjects were also found in obese patients with clinically diagnosed fatty change of the liver. CONCLUSION: Serum GGT fractionation by high-performance gel filtration liquid chromatography is potentially useful for the differential diagnosis of ALD and NAFLD.

Paradoxical effects of thyroid function on glomerular filtration rate estimated from serum creatinine or standardized cystatin C in patients with Japanese Graves' disease.

BACKGROUND: Estimated glomerular filtration rate (eGFR) is clinically valuable for evaluating renal function. Recently, serum cystatin C (sCysC) measurement has been standardized and has demonstrated utility as a novel indicator of renal function. Thyroid hormone is known to affect serum creatinine (sCr) and sCysC, however, the clinical significance of post-treatment renal function evaluation is yet to be completely elucidated. This study examined the effects of thyroid hormones on eGFR by sCr (eGFRCr), and standardized sCysC (eGFRCysC) in patients with Japanese Graves' disease (GD). METHODS: Serum samples were obtained from 113 outpatients with GD. Following pharmacotherapy, 41 of the 113 outpatients with GD achieved remission. Renal function was evaluated by eGFRCr and eGFRCysC. Reference method used Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. RESULTS: eGFRCr levels significantly increased whereas eGFRCysC levels significantly decreased with elevated FT3 and FT4 levels in patients with GD. In the remission group, eGFRCr levels significantly decreased and eGFRCysC levels significantly increased. No significant differences between eGFRCr and eGFRCysC levels were observed. Furthermore, CKD-EPI equations show a similar trend and eGFRCr-CysC levels were no significant differences regardless of before and after treatment. CONCLUSIONS: Renal function evaluation by eGFRCr and eGFRCysC had clinical utility in post-treatment euthyroidism.

Estimated glomerular filtration rate by serum creatinine or standardized cystatin C in Japanese patients with Graves׳ disease.

Glomerular filtration rate (eGFR) by serum creatinine (eGFRCr) or standardized cystatin C (eGFRCysC) were estimated in Japanese patients with Graves׳ disease (GD) of different sex. Clinical samples were collected from patients with GD with normal renal function to accurately validate eGFRCr and eGFRCysC levels and evaluate how hyperthyroidism affects renal function. Levels of eGFRCr and eGFRCysC showed clinical usefulness in successfully treated euthyroid patients with GD regardless of sex. The article includes detailed experimental methods and data used in our analysis. The data relates to the "Paradoxical effect of thyroid function on the estimated glomerular filtration rate by serum creatinine or standardized cystatin C in Japanese Graves' disease patients" (Suzuki et al., 2015) [1].

[Biochemical-Immunological Examination].

Abnormal laboratory values are often attributable to errors in pre-test processes, such as those in blood collection or sample treatment. Although these errors occur frequently, only a small percentage of them are detected, possibly resulting in misdiagnoses. In addition, when performing blood collection or sample treatment, not only doctors and nurses, but also medical technologists, who are conversant with laboratory tests, may generate abnormal values due to incorrect recognition or carelessness. On the other hand, although it is impossible to identify all abnormal values caused by pre-test errors in laboratories, the nonidentification of these errors will lead to iatrogenically abnormal values. Therefore, staff members conducting analyses are required to be familiar with many cases of abnormal values associated with blood collection, and to have skills to consider errors that may be responsible for the abnormal values identified. In this report, I present pre-test errors causing abnormal values, and measures against these errors.

The abnormal reaction data-detecting function of the automated biochemical analyzer was useful to prevent erroneous total-bilirubin measurement and to identify monoclonal proteins.

BACKGROUND: Recently, to detect abnormal reactions and failures of the device in biological analysis, a reaction data monitoring system has been provided for automated biochemical analyzers. We investigated the usefulness of this function for total-bilirubin (T-Bil) measurement in routine testing. METHODS: Abnormal reactions of T-Bil were detected in the reaction data over time based on the following items: whether the absorbance variance after mixing of the first reagent and sample exceeds the cut-off value. RESULTS: In the cases in which the abnormal reaction was observed, the absorbance rapidly rose because of turbidity after mixing the sample with Reagent-1. The measured value was higher than the actual T-Bil level, for which the analyzer showed a warning mark with the output data. When this particular serum sample was subjected to immunofixation electrophoresis, the presence of a monoclonal protein was confirmed. We encountered seven similar cases out of 30,731 samples. CONCLUSIONS: The reaction data monitoring system of the automated biochemical analyzers was useful to prevent false reports (misdiagnosis) due to unpredictable problems during T-Bil measurement. It was also suggested that detection of false reaction with a reagent may be a clue to find a new pathology, such as monoclonal gammopathy.

Alternative splicing of FBP-interacting repressor coordinates c-Myc, P27Kip1/cyclinE and Ku86/XRCC5 expression as a molecular sensor for bleomycin-induced DNA damage pathway.

The far-upstream element-binding protein-interacting repressor (FIR) is a c-myc transcriptional suppressor. FIR is alternatively spliced to lack the transcriptional repression domain within exon 2 (FIRΔexon2) in colorectal cancers. FIR and FIRΔexon2 form homo- or heterodimers that complex with SAP155. SAP155, a subunit of the essential splicing factor 3b subcomplex in the spliceosome, is required for proper P27Kip1 pre-mRNA splicing, and P27Kip1 arrests cells at G1. In contrast, FIR was co-immunoprecipitated with Ku86 and DNA-PKcs. siRNA against Ku86/Ku70 decreased FIR and P27Kip1 expression, whereas siRNA against FIR decreased Ku86/XRCC5 and P27Kip1 expression. Thus the mechanical interaction of FIR/FIRΔexon2/SAP155 bridges c-myc and P27Kip1 expression, potentially integrates cell-cycle progression and c-myc transcription in cell. Bleomycin(BLM) is an anticancer agent that introduces DNA breaks. Because DNA breaks generate the recruitment of Ku86/Ku70 to bind to the broken DNA ends, the possible involvement of FIR and Ku86/Ku70 interaction in the BLM-induced DNA damage repair response was investigated in this study. First, BLM treatment reduced SAP155 expression and increased FIR and FIRΔexon2 mRNA expression as well as the ratio of FIRΔexon2:FIR in hepatoblastoma cells (HLE and HLF). Second, FIR or FIRΔexon2 adenovirus vectors (Ad-FIR or Ad-FIRΔexon2) increased Ku86/Ku70 and P27Kip1 expression in vitro. Third, BLM decreased P27Kip1 protein expression, whereas increased P27Kip1 and γH2AX expression with Ad-FIRΔexon2. Together, the interaction of FIR/SAP155 modulates FIR splicing and involves in cell-cycle control or cell fate via P27Kip1 and c-myc in BLM-induced DNA damage pathway. This novel function of FIR splicing will contribute to clinical studies of cancer management through elucidating the mechanical interaction of FIR/FIRΔexon2/SAP155 as a potential target for cancer treatment.