IL17A and rheumatoid arthritis: [16] have previously reported that TNF in combination with IL17 induces LIF production by inflammatory fibroblasts in rheumatoid arthritis, and LIF in turn drives an autocrine feedback loop of fibroblast activation via STAT4 resulting in high secretion of IL6 as well as other key inflammatory markers such as IL33, IL8, IL11, IL1α and IL1β.