GZMB and rheumatoid arthritis: The findings that citrullination and granzyme B cleavage have the capacity to modify the repertoire of self-proteins present in target cells killed by CTLs coupled with the longstanding observation that RA is present in a subset of patients with T-LGL leukemia, supports the model that T-LGLs are drivers of RA development in individuals with concurrent leukemia and RA.