Do some viruses use growth hormone, prolactin and their receptors to facilitate entry into cells?

Abstract The molecular evolution of pituitary growth hormone and prolactin in mammals shows two unusual features: episodes markedly accelerated and, some species, complex families related proteins expressed placenta resulting from multiple gene duplications. Explanations these phenomena terms physiological adaptations seem unconvincing. Here, I propose an alternative explanation, namely that evolutionary features reflect the use hormones (and their receptors) as viral receptors. Episodes rapid can then be explained due to “arms races” which changes lead reduced interaction with virus, subsequent virus counteract this. Placental paralogues could provide decoys bind viruses, protect foetus against infection. hypothesis implies extensive introduced into hormone, receptors during course mammalian interactions, not endocrine adaptations.