组织兼容性 (Histocompatibility) 指将一个体的组织移植至另一个体时，其免疫系统的反应程度。兼容性越高，免疫(或称排斥)反应程度越低，甚至没有免疫/排斥反应发生。二个不同的个体有多「兼容」由其细胞的MHC串行(sequence)决定，而MHC串行源自父母的染色体，

表位（线性、构象）

抗体（单株抗体、多株抗体、自身抗体） · 多株 B 细胞反应 · 同种异型 · 同种型 · 遗传型

Histocompatibility, or tissue compatibility, is the property of having the same, or sufficiently similar, alleles of a set of genes called human leukocyte antigens (HLA). Histocompatibility and histocompatibility testing is most relevant for topics related to whole organ, tissue, or stem cell transplants. HLA is the human form of the major histocompatibility complex genes found in all vertebrates. On a population level there is a great number of different alleles at each HLA locus on Chromosome 6 at 6p21.3 in humans with new ones being continuously discovered. Each individual inherits two different HLA alleles. Each of these alleles contain six loci (location on the chromosome) which code for major histocompatibility complex (MHC) proteins. These genes are codominantly expressed meaning every individual expresses each of the inherited alleles, both paternal and maternal. This results in a mixture of different types of MHC proteins for every individual. The similarity or difference of one individual's HLA alleles, and therefore MHC proteins, to another person's is what makes the tissues either compatible or incompatible.