p16INK4a is a protein that plays a crucial role in regulating the cell cycle, specifically by inhibiting the activity of cyclin-dependent kinases (CDKs). This inhibition helps control cell division and prevents cells from proliferating uncontrollably, which is important for maintaining normal cellular function and preventing cancer. The gene that encodes p16INK4a is often studied in relation to various cancers, as mutations or deletions in this gene can lead to the loss of its regulatory function. This loss can contribute to the development of tumors, making p16INK4a a significant focus in cancer research and potential therapeutic strategies.