Although the molecular recognition of Ponatinib to ERK2 provided a new therapeutic approach for the treatment of malignant tumors, the corresponding structure of the Ponatinib–ERK2 complex is still elusive because the observed S-C bond distance is as long as 2.35 Å (PDB: 3W55), which is about 0.5 longer than the normally covalent S-C bond. This evidence concerns the gene MAPK1 and cancer.