Polymorphisms in TBX21 and STAT4 increase the risk of systemic sclerosis: Evidence of possible gene-gene interaction and alterations in Th1/Th2 cytokines. - Gourh P; Agarwal SK; Divecha D; Assassi S; Paz G; Arora-Singh RK; Reveille JD; Shete S; Mayes MD; Arnett FC; Tan FK (Arthritis & Rheumatism, 2009)