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.

The human GR exists in two forms, α and β, which are thought to be the result of alternative splicing of a single gene. Sequence analysis indicates that the α and β forms of human GR are 777 and 742 amino acids long, respectively. They are identical up to residue 727, after which they diverge. After ligand binding, the 94kDa GRα isoform has been observed to translocate from the cytoplasm to the nucleus where it regulates gene expression. In contrast, the 90kDa GRβ isoform does not appear to bind either glucocorticoid agonists or antagonists, and has been localized predominantly in the nucleus independent of hormone treatment in some human cell lines. Studies suggest that human GRβ might function as a dominant negative inhibitor of GRα activity.