Various ctDNAs such as p16 DNA, APC, GSTP1, TIG1, etc. have been shown to be hypermethylated in patients with BLCA,324,325 and there is a positive correlation between the frequency of methylation and the stage, so the methylation of ctDNA may be used as a biomarker for the diagnosis of BLCA.326,327 miRNAs in plasma and exosomes have been widely studied as potential biomarkers and therapeutic targets. Here, APC is linked to bladder transitional cell carcinoma.