STAT3 and cancer: We have shown that S1P is involved in chronic intestinal inflammation and colitis-associated cancer in a mouse model of inflammatory carcinogenesis [197]; that is, S1P contributes to the production of IL-6, which is regulated by nuclear factor kappa B and to the constant activation of the transcription factor, signal transducer and activator of transcription 3 (STAT3), resulting in the upregulation of S1PR1, and consequently the high expression of S1PR1 [197,198].