||Jeong Hun Kang, Junichi Inokuchi, Takahito Kawano, Masaharu Murata, Protein kinase Cα as a therapeutic target in cancer, Nova Science Publishers, Inc., 25-47, 2018.01, Based on structural and activation characteristics, the protein kinase C(PKC) family can be classified into three isozymal subtypes: conventional or classic (cPKCs: α ΒI, ΒII and γ), novel or non-classic (nPKCs: δ, ε, η and θ) and atypical (aPKCs: ζ, ι and λ). Among cPKC isozymes, PKCa acts directly and/or indirectly in a variety of signaling mechanisms in cancer cells, including proliferation, survival, invasion, migration, apoptosis and drug resistance. Furthermore, overexpression of PKC α has been reported in bladder, breast, lung, ovarian, prostate and pancreatic cancer, as well as melanoma and glioma. Because of its key roles in cancer cells, PKC α is considered to be a promising therapeutic target. Several PKC α-targeted therapeutic molecules have been developed, and clinical trials to evaluate their efficacy and safety in cancer patients have been performed. This chapter primarily focuses on the expression pattern and function of PKC α in cancer cells, and newly emerging PKCα-targeted cancer therapies..