STAT3 and rheumatoid arthritis: Interestingly, Rajala et al. analyzed the clonal diversity of STAT3 mutations in LGLL in the same cohort; they found that 17% of the STAT3-mutated patients harbored multiple mutations, and that compared to STAT3-wild-type patients, RA was significantly more common in patients with T-LGLL carrying single (23% vs. 6%) or multiple STAT3 (43% vs. 6%) mutations [63].