Although high expression of fucosylated epitopes has been observed in many human colorectal cancer cell lines (Holst et al. 2016), our MC38 wild type cells did not express any fucosylated type I or type II Lewis antigens on their cell surface (Supplementary Figure 1A) and were completely devoid of Fut4 and Fut9 gene expression (Supplementary Figure 1B). The gene discussed is FUT4; the disease is colorectal cancer.