ADRB2 and asthma: A meta-analysis of case-control studies, including 46 studies, analyzing the association of ADRβ2 polymorphisms and the risk of asthma identified four single-nucleotide polymorphisms (SNPs): Arg16Gly (A46G, rs1042713), Gln27Glu (C79G, rs1042714), Thr164Ile (C491T, rs1800888), and Arg19Cys (T-47C, rs1042711) [83].