The use of BET protein inhibitors, already described as potential therapeutic agents in human breast cancer (Andrikopoulou et al., 2020; Khandekar and Tiriveedhi, 2020), is also a promising therapy in canine mammary cancer, as they can downregulate several genes related to self-renewal pathways, such as WNT, NOTCH, Hedgehog, and PI3K/AKT/mTOR (Xavier et al., 2019). This evidence concerns the gene MTOR and breast cancer.