CXCL1 and cancer: While TRAIL expression on activated NK and T cells increases their cytotoxicity, CXCL1 induction of TRAIL on BCSCs can turn them into apoptosis inducers, which suppress neighbor cancer cells (Griffith et al., 2000; Koyama et al., 2002; Papageorgiou et al., 2004), but also T cell activation and proliferation, favoring tumor immune evasion (Inoue et al., 2002).