P2RX2 and lung carcinoma: We also showed that contrast with the unfavorable prognosis of pyrimidine metabolic rate–limiting enzymes, purinergic receptors P2RX1, P2RX2, P2RX7, P2RY12, P2RY13, and P2RY14 were favorable prognostic markers in patients with lung cancer (Fig. 5b).