Fig. 1. Three distinct lymphomagenic pathways in AITL.
Our statistical analysis has identified three potentially distinct lymphomagenic pathways in AITL. The classic pathway accounts for approximately 60% of AITL cases and is characterized by the RHOA G17V mutation in association with several other recurrent mutations. The alternative pathway accounts for approximately 25% of AITL cases and is characterized by mutations in VAV1 or potentially other members of the Rho family of GTPases or their regulatory proteins. The mutations that drive the remaining approximately 15% of AITL cases are unknown. It is possible that mutations in signaling pathways directly regulating TFH differentiation contribute to these cases