WD repeat domain phospoinositide-interacting protein 2 (WIPI2) was identified as the mammalian homologue of yeast Atg18 (Polson et al. 2010). Like the other WIPI proteins, it binds PI(3,5)P2 and is recruited to autophagosomal membranes, especially upon autophagy induction (Proikas-Cezanne et al. 2015). WIPI1, WIPI2 and WIPI4 all localize to the initiating autophagosome during autophagy (Proikas-Cezanne et al. 2007, Obara et al. 2008, Polson et al. 2010). WIPI2 has been found to specifically bind to ATG16L1, thereby recruiting the ATG12:ATG5:ATG16L1 complex that is required for LC3 lipidation (Dooley et al. 2014).