We subsequently verified this regulation in the serum and CSF of patients with clinically confirmed severe Cbl deficiency (i.e., those with pernicious anaemia and/or subacute combined degeneration) (5), and then investigated the role of EGF in multiple sclerosis (MS) because subacute combined degeneration is still considered in the differential diagnosis of early MS (6–8); and some cases of late-onset CblC disease [a genetic defect of Cbl metabolism with a CNS histopathological picture that is similar to that of subacute combined degeneration (5)] have been described as resembling MS (9). Here, EGF is linked to myeloid sarcoma.