We found significant enhanced levels of total Th17 lymphocytes (defined as CD4+IL-17+) as well as enhanced numbers of their pathogenic (defined as CD4+CXCR3+IL-17+IL-22+CD243+CD161+IFN-γ+IL-10−) and nonpathogenic (CD4+CXCR3+IL-17+IL-22−CD243−CD161−IFN-γ−IL-10+) cell subsets in patients with RA. The gene discussed is ABCB1; the disease is rheumatoid arthritis.