RETRACTION: K. Shigeta, M. Hasegawa, E. Kikuchi, Y. Yasumizu, T. Kosaka, R. Mizuno, S. Mikami, A. Miyajima, D. Kufe and M. Oya, “Role of the MUC1‐C Oncoprotein in the Acquisition of Cisplatin Resistance by Urothelial Carcinoma,” Cancer Science 111, no. 10 (2020): 3639–3652, https://doi.org/10.1111/cas.14574. Here, MUC1 is linked to urothelial carcinoma.