The recently published GPR4 blocker, NE 52-QQ57 (Velcicky et al., 2017), represents a promising new family of drugs, because GPR4 is one of the potential targets in cancer therapy (Castellone et al., 2011; Damaghi et al., 2013) and inflammatory responses (Chen et al., 2011; Dong et al., 2013). Here, GPR4 is linked to cancer.