['Asthma, one major respiratory consequence, might be caused by a complex interaction between multiple candidate genes and environmental factors. Herein, we aimed to investigate whether Janus kinase (JAK)-1 gene polymorphisms are associated with asthma susceptibility.', 'Patients were divided into two groups: (1) asthma (n=117) and (2) nonasthma (n=60). The JAK-1 polymorphisms (rs2780895, rs10789166, rs4916008, rs2780885, rs17127114, and rs3806277) were amplified by polymerase chain reaction and detected by electrophoresis after restriction enzyme (HpyCH4IV, Tsp45I, HpaII, XmnI, MspI, and HpaII) digestions. Genotypes, allelic frequencies, and association of haplotypes in both groups were compared.', 'JAK-1 rs2780895 gene polymorphism is associated with susceptibility to asthma. Distributions of JAK-1 rs2780895*CC/CT/TT and C/T allele in both groups are: (1) 80/4/16% and 82/18%; (2) 48/45/7% and 71/29%. Other 5 JAK-1 SNPs (rs10789166, rs4916008, rs2780885, rs17127114, and rs3806277) are not associated with asthma susceptibilities. Distributions of JAK-1 rs10789166*AA/AG/GG, rs4916008*CC/CT/TT, rs2780885*CC/CT/TT, rs17127114*AA/AG/GG, rs3806277*AA/AG/GG in both groups are: (1) 50/40/10%, 42/49/9%, 50/40/10%, 9/37/54%, 8/35/57%; (2) 43/50/7%, 40/50/10%, 50/43/7%, 7/48/45%, 6/42/52%. Haplotype analyses for JAK-1 gene polymorphisms (rs2780895-rs10789166-rs4916008-rs2780885-rs17127114-rs3806277) revealed that JAK-1 haplotypes are not associated with asthma susceptibilities.'] Are jAK-1 rs2780895 C-related genotype and allele but not JAK-1 rs10789166 , rs4916008 , rs2780885 , rs17127114 , and rs3806277 associated with higher susceptibility to asthma?