Recent reports have shown that the CCRL1 ligands promote proliferation and prevent apoptosis (Wang et al. 2005; Li et al. 2009; Shen et al. 2009; Johnson et al. 2010; Xu et al. 2011, 2012), suggesting that increased expression of Ccrl1 may reduce tumor response through chemokine depletion. Here, ACKR4 is linked to neoplasm.