A diagram of the full length of KRAS4A and KRAS4B is drawn, which contains the G domain and hyper variable region (HVR). To distinguish KRAS4A and KRAS4B, different colors are utilized, and the amino acid sequence of the HVR is indicated with abbreviations. For the G domain, the PTMs between KRAS4A and KRAS4B are similar, including ubiquitination, glycosylation, sumoylation, phosphorylation, acetylation, nitrosylation, and ADP-ribosylation. Within the HVR, specific modifications and related residues share the same color.