Interestingly, LIF anti-tumorigenic effects in breast cancer [16,30] and clear cell renal carcinoma [31] were found to involve the kinase core of the Hippo pathway while LIF pro-tumorigenic effects in melanoma pass through the JAK/STAT pathway activation [25], showing how the contradictory effects of LIF in cancer depend on the cellular mechanisms involved. Here, LIF is linked to breast cancer.