Protein kinase C (PKC) isoenzymes play a crucial role in signal transduction, with distinct structural and functional characteristics. PKC is a family of isoenzymes that differ in their structure, expression in various tissues, activation mechanisms, and substrate specificity. These differences suggest that different PKC isoenzymes may lead to divergent responses in signal transduction pathways. The review discusses the structure, biochemical properties, and expression patterns of PKC isoenzymes, highlighting their roles in cellular processes such as proliferation and differentiation. PKC isoenzymes are divided into two main groups: conventional PKCs (cPKCs), which require Ca²+ for activation, and novel PKCs (nPKCs), which are Ca²+ independent. The review also explores the regulation of PKC isoenzymes, including their expression in different tissues and cell lines, and their involvement in various cellular functions. The study of PKC isoenzymes has revealed their importance in signal transduction, with different isoenzymes potentially playing distinct roles in cellular responses. The review emphasizes the need for further research to fully understand the diverse functions of PKC isoenzymes in signal transduction and their implications for cellular processes.Protein kinase C (PKC) isoenzymes play a crucial role in signal transduction, with distinct structural and functional characteristics. PKC is a family of isoenzymes that differ in their structure, expression in various tissues, activation mechanisms, and substrate specificity. These differences suggest that different PKC isoenzymes may lead to divergent responses in signal transduction pathways. The review discusses the structure, biochemical properties, and expression patterns of PKC isoenzymes, highlighting their roles in cellular processes such as proliferation and differentiation. PKC isoenzymes are divided into two main groups: conventional PKCs (cPKCs), which require Ca²+ for activation, and novel PKCs (nPKCs), which are Ca²+ independent. The review also explores the regulation of PKC isoenzymes, including their expression in different tissues and cell lines, and their involvement in various cellular functions. The study of PKC isoenzymes has revealed their importance in signal transduction, with different isoenzymes potentially playing distinct roles in cellular responses. The review emphasizes the need for further research to fully understand the diverse functions of PKC isoenzymes in signal transduction and their implications for cellular processes.