PIK3CA and neoplasm: As a chaperone protein well-known for its role in stabilizing various growth factor receptors (such as tumor necrosis factor receptors (TNFRs) and NF-κB) and various signaling molecules found overexpressed in tumor cells (including PI3K and AKT proteins), inhibition of HSP90 was reported to downregulate the PI3K/AKT pathway, thus resulting in apoptosis of tumor cells via downregulation of the antiapoptotic protein, BCL-w 78-81.