Single missense mutation as a signal of indolent thymic epithelial tumors: General Transcription Factor II-I (GTF2I)

Hyun-Sung Lee, Cynthia Y. Truong, Hee-Jin Jang, Bryan M. Burt


Thymic epithelial tumors (TETs) are enigmatic malignancies consisting of diverse components of lymphocytes and epithelial cells (1) and we are only beginning to understand the molecular determinants of these tumors (2-8). Petrini and colleagues (2) first reported the identification of a missense mutation in general transcription factor II-I (GTF2I) (p.Leu424His in change to codon chromosome 7 c.74146970T>A) that highly occurred in type A thymomas demonstrating favorable survival (2). GTF2I β and δ isoforms are expressed in TETs, and in vitro experiments showed that both mutation isoforms could stimulate cell proliferation.