The KLLN gene provides instructions for making a protein called killin. The activity of the KLLN gene is controlled by a protein called p53 (which is produced from the TP53 gene). Little is known about the function of killin, although it is thought to trigger cells to self-destruct (undergo apoptosis) when they are damaged or no longer needed. In this way, killin helps to prevent abnormal cells from growing and dividing unchecked to form tumors. Through its role in regulating cell division, killin helps maintain the stability of a cell's genetic information. Based on these roles, killin is thought to be a tumor suppressor.