SMAD6 and urinary bladder cancer: Moreover, in two additional bladder cancer cell lines, UM-UC-3 and RT112, SMAD6 knockdown (Supplementary Fig. 7b) partially reversed the reduction in cell viability (Supplementary Fig. 7c) and partially reversed the increase in caspase3/7 activity caused by YTHDC1 overexpression (Supplementary Fig. 7e, right).