In addition, a retrospective study found that the absolute and relative counts of CD3−CD56+ NK cells in the peripheral blood of patients with RA-ILD were higher than those of patients with RA, whereas the percentages of T cells and CD4+ T cells were lower, suggesting that the occurrence of RA-ILD may be unbalanced with the lymphocyte subsets of patients. The gene discussed is CD4; the disease is rheumatoid arthritis.