IL17A and rheumatoid arthritis: However in RA SFMC, significantly more IL-17-positive CD4 T cells coexpressed TNFα (94.55% (88.06 to 97.77)) compared with only 72.22% (61.29 to 87.43) found in matched RA PBMC (P = 0.0068) and 79.27% (61.80 to 89.87) in healthy control PBMC.