The activities of Ca⁺²-PL dependent protein Kinase (PKC) and independent protein kinase(RKM) were measured in human stomach and breast tumors and in the respective counterparts of normal tissue. Expression of c-fos and c-myc of the tissues were also measured. RNAs of c-fos and c-myc were unexpectedly high in the tissue from normal stomach and breast as well as in all cancer tissue. On the other hand, cytosolic and particulate PKC activities were higher in the tumors as compared to those of normal controls. Notably, some cases exhibited. altered activities of PKC i.e. increased RKM activities as high as RKC, which might be related to the autocrine control of growth in the tumor mass.