IL4 and asthma: Based on all mentioned above, we aimed to describe the effect of genetic variants type SNPs and CNVs in IL4 (rs2070874 C/T, nsv528281 and nsv529021), and IL13 (rs1800925 C/T and rs20541 G/A) genes in the asthma susceptibility, and the possible effect in the serum levels of IL-4, IL-13, IgE and the potential effects implied in the risk environmental exposure factors.