CDG-IIb is a genetic disorder affecting the N-glycosylation process and, specifically, results in a defect in the processing of N-glycans due to an absence of functional α-glucosidase I. Cells from the siblings with CDG-IIb and healthy donors were collected and tested for susceptibility to four strains of HIV, Influenza A (H1N1), and Adenovirus type 5. This evidence concerns the gene MOGS and congenital disorder of glycosylation.