IL6 and COVID-19: Moreover, the multivariate analysis demonstrated that ACE-2 CT + TT, IFITM-3 AG + GG variants, and IL-6 were independent risk factors for COVID-19 severity and clinical progression with odds ratios (95% C. I) of 12.136 (2.784–52.896), 17.276 (3.673–81.249), and 1.032 (1.012–1.052) (p = 0.001, p < 0.010, and p = 0.002), respectively.