CDK5RAP3 also known as HSF-27 is a protein that has been reported to function in signaling pathways governing transcriptional regulation and cell cycle progression. CDK5RAP3 plays a crucial role in neuronal differentiation, cell proliferation, and DNA repair, making CDK5RAP3 an important target for research in neurobiology and cancer. CDK5RAP3 is primarily located in the cytoplasm and interacts with the Cdk5 activator protein p35, which is essential for activating Cdk5′s enzymatic activity. This interaction is particularly significant during neuronal differentiation, as increased Cdk5 activity is observed at this stage. CDK5RAP3 functions as a regulatory component of the G2/M DNA damage checkpoint, responding to genotoxic stress, and is expressed in various tissues, including the brain, heart, placenta, liver, skeletal muscle, lung, kidney, and pancreas, with overexpression noted in tumor tissues.