chalone In mammalian epithelial tissue (see EPITHELIUM), a tissue-specific protein of moderate size, or a simple polypeptide, that in the presence of adrenalin inhibits mitosis in cells. The loss of chalones from damaged cells stimulates and directs wound healing. Chalones are thought to be important in ageing and cancer.

chalone Any one of a group of compounds that inhibit mitosis. This action was originally demonstrated in vitro, using preparations of mammalian cells and tissues; chalones are now thought to be inhibitory growth factors.