IL2 and infection: This was confirmed by the amount of IL-2 cleaved by phosphatidylinositol-specific phospholipase C (PI-PLC) from membrane associated GPI-anchored IL-2 in vitro and in vivo (Fig. 1c, d), and the amount of either secreted IL-2 or membrane-bound IL-2 was correlated to the multiplicity of infection (MOI) of viruses (Fig. 1a–c).