WIPI-1 (WD-repeat protein interacting with phosphoinosides) is highly expressed in a variety of tumors. It interacts with phosphatidylinositol-3-P and this interaction is required for recruitment to membranes. WIPI-1 contains the signature motif LXXLL for nuclear receptor association and it binds to estrogen and androgen receptors in vitro. The WIPI-1 homolog in S. cerevisiae (Atg18) plays a role in autophagy. WIPI-1 accumulates in multi-membrane structures under autophagic conditions and it co-localizes with LC3.