Phenomenon in genetics that one gene (a pair of alleles) suppresses the operation of another gene (pair of alleles). Epistasis is a type of a non-Mendelian inheritance pattern. Epistasis comes in different types.
Epistasis may also occur between three or more genes, in quantitative genetics.
NT: dominant epistasis ↔ recessive epistasis ↔ cumulative isomery ↔ non-cumulative isomery ↔ reciprocal dominant epistasis ↔ reciprocal recessive epistasis
BT: non-Mendelian inheritance