DEFA1 and COVID-19: Interestingly, In the COVID-19 negative group, VDR expression was positively correlated with CCL20 expression (r = 0.59, p < 0.01), while no significant correlation was observed between VDR and DEFA1-3 (r = –0.15) or between CCL20 and DEFA1-3 (r = –0.04).