To investigate the hypothesis that melanoma growth in bone promotes the egress of Th1 cells and NK cells from the intestine through an S1PR1/5-mediated mechanism, animals were injected with B16-F10 cells and treated for 3 weeks with the S1PR1 functional antagonist FTY720, the S1PR5 functional antagonist BAF312, or both FTY720 and BAF312. The gene discussed is S1PR1; the disease is melanoma.