CCNB1 and bladder transitional cell carcinoma: Furthermore, the mRNA levels of cyclin B1 (CCNB1) and cyclin E1 (CCNE1), which are markers of mitosis, exhibited a positive correlation with IGF2BP3 expression in TCGA BLCA (r = 0.37, r = 0.3, respectively) (Fig. 5D, E).