A study showed that SUMOylation at Lys99 residues of USP28 could inhibit the activity of USP28 (Table 3), indicating potential therapeutic role in colon cancer cells and NSCLC cells (Diefenbacher et al., 2014; Zhen et al., 2014; Zhang L. et al., 2015). Here, USP28 is linked to malignant colon neoplasm.