What is human leukocyte antigens (hla)?

Tissue antigens. The human leukocyte antigen (hla) system is the name of the major histocompatibility complex (mhc) in humans, which contains genes related to immune system function in humans. This group of genes resides on chromosome 6 and encodes cell-surface antigen-presenting proteins. They are important in disease defense and can be the cause of organ transplant rejections, hence tissue typing.