We analyzed the genetic variants located on TMPSSR2, PCSK3, DPP4, and BSG coding-region in a representative cohort of Italian patients affected by COVID-19, in order to verify the hypothesis that the COVID-19 susceptibility is also influenced by genetic variability of genes coding for proteins involved in the entry of SARS-CoV-2 into target cells. This evidence concerns the gene DPP4 and COVID-19.