CFTR and COVID-19: The work also characterized complex CFTR alleles, including p.[Ala238Val;Phe508del], p.[Ala238Val;Phe508del], p.[Arg74Trp;Val201Met;Asp1270Asn], p.[Ile1027Thr;Phe508del], and p.[Ile1506Val;Asp1168Gly] ([I506V;D1168G]), and the simple variants p.Arg347Cys (R347C), p.Phe1052Val (F1052V), p.Tyr625Asn (Y625N), p.Ile328Val (I328V), p.Lys68Glu (K68E), p.Ala309Asp (A309D), p.Ala252Thr (A252T), p.Gly542Ter (G542X), p.Val562Ile (V562I), p.Arg1066His (R1066H), p.Ile506Val (I506V), and p.Ile807Met (I807M), which lead to a decrease in CFTR function and, thus, to a more severe COVID-19 course.