Protein kinase B (AKT) PI3K / AKT / mTOR signaling pathways play a crucial role in modulating cell survival, proliferation, metastasis, metabolism, angiogenesis, and apoptosis. The AKT family consists of three isoforms: AKT1, AKT2, and AKT3. Moreover, it has high sequence homology in the kinase domain and has similar substrate specificity to other members of AGC protein kinase. Recent studies have shown that AKT signals disappear in some tumors. Overexpression and activation of AKT are not sufficient to induce the phenotype of malignant tumors. However, many studies have shown the importance of AKT in carcinogenesis including, breast and prostate cancers, second and third global cancer burden, respectively, in terms of incidence and death. Inhibition of AKT signaling may be beneficial in terms of therapeutic use and understanding of the function of AKT. To date, limited numbers of AKT inhibitors have been identified, and none are strongly selective for AKT isoforms. In this regard, we discussed the current insight of AKT inhibitors in drug development, protein structure, and mechanism as well as the role of AKT in the development of drug targets for breast cancer and prostate cancer.