MAPK3 and urothelial carcinoma: Similarly, p38 kinase expression was elevated, whereas ERK1/2 expression was reduced in bladder tumor tissues compared to adjacent normal bladder tissues.<h4>Conclusions</h4>These findings suggest that CacyBP/SIP may play a critical role in urothelial carcinoma progression by modulating ERK1/2 and p38 kinase activity.