Exerts an anti-apoptotic effect in the immune system and is involved in responses to infections. Spleen, thymus and T-cells. Greatly reduced in T-cells from lymphopenic rats. Belongs to the TRAFAC class TrmE-Era-EngA-EngB-Septin-like GTPase superfamily. AIG1/Toc34/Toc159-like paraseptin GTPase family. IAN subfamily.