Recapping the role of HSP90 discloses its broad-ranging regulation of many oncogenic kinases and transcription factors, including p53, HIF-1α, CDK4, BRAF, HER2, ERBB2, AKT, MEK, hTERT, and survivin [182,183]; hence, an inhibition of HSP90 affects many physiological and tumor processes, including angiogenesis inhibition in many tumors [184,185]. Here, CDK4 is linked to neoplasm.