Given that S1P may be critically linked to metastasis [402,403], it may be worth considering, in addition, the interesting work demonstrating that deletion of DR5 induce cell motility and promotes cell invasion in a TRAF2 and S1P-dependent manner, through activation of the JNK/AP-1 pathway in lung cancer cells [368,404] (Figure 4). Here, MBTPS1 is linked to lung cancer.