Determination of METTL3 and CDCP1 expression in human cystitis and bladder cancer tissues revealed that METTL3 and CDCP1 expressions are weak or not detectable in majority of the cystitis samples, although the METTL3 and CDCP1 are upregulated in the non-muscle-invasive bladder cancer samples. Here, METTL3 is linked to cystitis.