SIVcpz, or Simian Immunodeficiency Virus from chimpanzees, is a type of virus that affects primates. It is closely related to the human immunodeficiency virus (HIV) and is primarily found in African chimpanzees. SIVcpz is significant in studies of HIV because it helps researchers understand how the virus evolved and crossed over to humans. The transmission of SIVcpz to humans is believed to have occurred through activities such as hunting and consuming chimpanzee meat. This cross-species transmission is a key factor in the emergence of HIV-1, the most common and pathogenic strain of HIV in humans. Understanding SIVcpz aids in the development of treatments and preventive measures for HIV/AIDS.