MAP2K4 and breast cancer: constructed a mouse 4T1 breast cancer model in their study, and the results showed that the total number of Treg cells in the tumor microenvironment decreased and the number of apoptotic Treg cells increases, and XHP regulates the expression of the Treg-related genes MEKK1, SEK1, JNK1, and AP-1, which inhibit breast cancer progression (113).