TMPRSS2 and diabetes mellitus: On the other hand, a report by Baristaite and Gurwitz revealed that 25 mM D-galactose, applied in order to induce a diabetes-like phenotype, can stimulate mRNA synthesis of TMPRSS2, ACE2, and FURIN in A549 human lung epithelial cancer cells [223], which may suggest their participation in the development of COVID-19-related symptoms in the respiratory system of diabetic patients.