Kato et al (2001) reported that the respective mean IC50 values for Cox-1 and Cox-2 IC50 (10−6 M), and the Cox-1/Cox-2 ratio of each drug were as follows: celecoxib, 82, 6.8, 12; etodolac, >100, 53, >1.9; NS-398, 125, 5.6, 22. Indeed etodolac has the lowest Cox-2 selectivity and highest Cox-2 IC50 (5.3 × 10−5 M) among the three COX-2 inhibitors in their experiments. From these data, Cox-2 inhibition might not directly contribute to the in vivo tumour growth inhibitory effect and reversal EMT effect in human bladder cancer cells that we used here. Here, PTGS2 is linked to urinary bladder cancer.