Age-dependent complementation of the B (MHC) alleles and a non-B allele controlling resistance to progression of Rous sarcomas, and genetic independence of resistance to induction of tumours in the model of inbred lines of chickens.

The effect of age on the resistance to progression of Rous sarcomas was investigated in chickens of different inbred lines and their hybrids. This genetic resistance depends on complementation of B-linked genes and complementation of genes outside the B complex. The reduction of tumour inducibility is controlled by genes outside the B complex, and this type of resistance is independent of the resistance to tumour progression that is primarily controlled by B-linked genes.