The results indicated that the abundance of the vast majority of mycobiota prevalent in the healthy controls was negatively correlated with some serological features of RA; in contrast, the enrichment in RA patients was positively correlated with some serological characteristics of RA, except Wallemia, which was negatively related to the serum levels of IgG, IgA and CA125. The gene discussed is CD79A; the disease is rheumatoid arthritis.