A variant of R6BD-based peptide or peptidomimetic with high affinity to the peptide-binding groove (PBG) of MAGEA4 has the potential to be a therapeutic agent in cancers overexpressing MAGEA4 and RAD18 (Xie et al, 2014; Wu et al, 2019; Li et al, 2022; Du et al, 2022; Bhan et al, 2012; Fujiwara-Kuroda et al, 2018; Sani et al, 2018). Here, MAGEA4 is linked to cancer.