IGF1 and triple-negative breast carcinoma: According to the literatures, Insulin‐like growth factors (IGFs) stimulated cell proliferation by activated MAPK, Akt 31 and S1P have been found to inhibit keratinocyte proliferation through inhibit Akt/PKB pathway induced by Insulin‐like growth factor I (IGF‐I).32 In the cancer condition, triple negative breast cancer was reported to express high level of IGF‐I.31, 33 Therefore, S1P/S1PR1 signaling might downregulate IGF‐1/Akt/PKB axis to suppress cell proliferation.