PTGR1 and urinary bladder cancer: Overexpressed PTGR1 was found in many cancer cell lines, such as hepatocellular carcinoma (Sánchez-Rodríguez et al., 2017), lung cancer (Zhao et al., 2010), prostate cancer (Xue et al., 2016), and bladder cancer (Tapak et al., 2015), suggesting that PTGR1 has an oncogenic role.