LEP and breast carcinoma: Also in this case, most studies focus on breast cancer, where leptin acts as a positive regulator of Notch expression and activation in estrogen responsive and triple-negative breast cancer (TNBC) cells through canonic JAK2/STAT, MAPK1/2K 1/2, and PI3K/AKT, and non-canonic signaling pathways JNK and p38 MAP kinases (189, 190).