Objective: To explore the diagnostic value of serum severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) protein assay in the early stages of SARS-COV-2 infection. Methods: Serum N protein level in SARS-COV-2 infected patients and non-SARS-COV-2 infected population was measured by enzyme-linked immunosorbent assay (ELISA) double antibody sandwich assay. Colloidal gold immunochromatography assay was used to detect serum N protein antibodies in the above populations. Results: Fifty cases of SARS-CoV-2 nucleic acid-positive and SARS-CoV-2 antibody-negative patients had a serum N protein positivity rate of 76%. Thirty-seven patients who were positive for serum SARS-CoV-2 antibody after infection had a serum SARS-CoV-2 N protein positivity rate of 2.7%. Serum N protein test results of 633 non-SARS-COV-2 infected patients, including pregnant women, patients with other respiratory infections, and individuals with increased rheumatoid factor were all negative, with serum N protein concentration <10.00 pg/mL at 100% specificity. Using SPSS 19.0 to calculate the receiver operating characteristic curve, the area under the curve was determined to be 0.9756 (95% confidence interval 0.9485-1.000, p < 0.0001), and sensitivity and specificity were 92% (95% confidence interval 81.16-96.85%) and 96.84% (95% confidence interval 95.17-97.15%), respectively. The best CUTOFF value was 1.850 pg/mL. Conclusion: The measurement of serum SARS-COV-2 N protein has a high diagnostic value for infected patients before the antibody appears and shortens the window period of serological diagnosis. It is recommended that the manufacturer establish two different CUTOFF values according to the purpose of the application. One CUTOFF value is used for the diagnosis of clinical SARS-COV-2 infection, and the other is used to screen out as many suspected cases as possible.

N6-Methyladenosine (m6A), the most abundant internal modification associated with eukaryotic mRNAs, has emerged as a dynamic regulatory mechanism controlling the expression of genes involved in many physiological activities by affecting various steps of mRNA metabolism, including splicing, export, translation, and stability. Here, we review the general role of m6A, highlighting recent advances related to the three major types enzymes that determine the level of m6A modification (i.e., writers, erasers, and readers) and the regulatory mechanism by which m6A influences multiple stages of RNA metabolism. This review clarifies the close connection and interaction between m6A modification and nuclear gene expression, and provides key background information for further studies of its roles in numerous physiological and pathophysiological processes. Among them, perhaps the most eye-catching process is tumorigenesis. Clarifying the molecular mechanism of tumorigenesis, development and metastasis in various tissues of the human body is conducive to curbing out-of-control cell activities from the root and providing a new strategy for human beings to defeat tumors.