EGFR and familial primary hypomagnesemia: Demizu et al. [74] formulated an in-hospital manual indicating “to start oral magnesium oxide from the start of cetuximab treatments and, in patients who develop hypomagnesemia, to start intravenous (IV) infusion of magnesium sulfate from the onset of point of grade 1 (CTCAE) hypomagnesemia” for patients receiving cetuximab, an anti-EGFR antibody.