F2RL1 and cancer: The contribution of the acid-sensing ion channels (ASICs) has been reported in an osteolysis-induced bone cancer pain (Nagae et al., 2007) and the protease-activator receptor 2 (PAR2) in peripheral neurons is the target of serine proteases and tryptase released from cancer cells to promote the prolonged mechanical allodynia in mouse cancer nociceptive models (Lam and Schmidt, 2010).