The PTDM develops in the consequence of the presence of predisposing factors (which are similar to type 2 diabetes mellitus) as well as risk factors related to the transplantation, among which the most important are the following: metabolic adverse effects of immunosuppressive therapy with calcineurin inhibitors, mammalian target of rapamycin inhibitors (mTORi), and corticosteroids, infections with cytomegalovirus (CMV) and hepatitis C virus after the transplantation and hypomagnesemia [33,34,35,36]. The gene discussed is MTOR; the disease is diabetes mellitus.