Another important finding implicates that defects in the innate response could also contribute to recurrent infections in BS patients, since another group of differentially expressed genes observed in our work includes AZU1, BPI, CAMP, CTSG, DEFA4, LTF, PPBP, HP, and CXCL1, which play role in regulation of innate immunity. This evidence concerns the gene PPBP and infection.