S1PR1 and obesity due to melanocortin 4 receptor deficiency: In conclusion, S1P/S1PR initiated the feedback loops, whereby S1P-S1PR1/S1PR3-YAP signaling mediated lymphomagenesis contributed to tumor aggressive growth, and S1P-ALOX15 signaling mediated TAMs contributed to immunosuppressive microenvironment in obesity-lymphoma.