The human P53 protein functions as a tumor suppressor. Mdm2 is an important negative regulator of the p53 tumor suppressor. Point mutations in multiple tumor suppressor proteins cause cancer. This gene functions as a tumor suppressor. Many of the pathway components recognized as tumor suppressor genes are mutated in human cancers. Other factors are mutations in or total loss of tumor suppressor genes. These processes are orchestrated by proteins known as tumor suppressor genes. CD9 can be a tumor suppressor or promotor. MDM2 is a repressor of protein 53, which itself is a tumor suppressor. In 1992 oncomice with tumor suppressor genes knocked out were generated. The rifle can also be fitted with a quick detachable sound suppressor and a bayonet. The muzzle is threaded for a flash suppressor or blank-firing device. The rifle can be used with a sound suppressor. T91 has a barrel with flash suppressor. The M1918 has a cylindrical flash suppressor fitted to the muzzle end.