In vitro, ULP-3 processes the NEDD8 C-terminal similarly to NEDP1, whereas in vivo, overexpression of ULP-3 in human cancer cells decreases NEDDylation of L11, a previously characterized NEDD8 substrate (Xirodimas et al., 2008) and has no effect on total ubiquitination. Here, NEDD8 is linked to cancer.