Анотация: The current state of knowledge of milk-protein coding genes and prolactin is presented in this review. Genes encoding milk proteins (caseins and whey proteins) are discussed as well as the genes of the factors regulating expression milk protein genes, such as prolactin, prolactin receptor, and the genes of the somatotropic (somatotropin growth hormone) axis (growth hormone, GH-releasing hormone, Pit1 ЦPituitary-specific Transcription Factor-1, growth hormone receptor, insulin-like growth factor 1, and STAT5A- Signal Transducers and Activators of Transcription). Also findings on diacylglycerol acyltransferase 1 and leptin genes are reviewed in terms of milk yield traits of dairy cattle