Flow of study identification, inclusion, and exclusion.

<p>Flow of study identification, inclusion, and exclusion.</p

Funnel plot for publication bias in selection of studies on the <i>CTLA-4</i> −318 C/T polymorphism (CC+CT vs. TT).

<p>Funnel plot for publication bias in selection of studies on the <i>CTLA-4</i> −318 C/T polymorphism (CC+CT vs. TT).</p

Meta-analysis with a random-effects model for the association between asthma risk and the <i>CTLA-4</i> +49 A/G polymorphism (AA vs. AG+GG).

<p>Meta-analysis with a random-effects model for the association between asthma risk and the <i>CTLA-4</i> +49 A/G polymorphism (AA vs. AG+GG).</p

Characteristics of the case-control studies included in meta-analysis.

*<p>Data for atopic or non-atopic asthma patients could be separately extracted.</p><p>ATS, American Thoracic Society; NHLBI, The National Heart, Lung, and Blood Institute; WHO, The World Health Organization; NIH, National Institutes of Health; SPT, skin prick test to common aeroallergens; RAST, radioallergosorbent test; PCR, polymerase chain reaction; RFLP, restriction fragment length polymorphism; TaqMan-ASA, TaqMan allele-specific amplification method; NA, not available.</p

Meta-analysis with a random-effects model for the association between asthma risk and the <i>CTLA-4</i> −318 C/T polymorphism (CC+CT vs. TT).

<p>Meta-analysis with a random-effects model for the association between asthma risk and the <i>CTLA-4</i> −318 C/T polymorphism (CC+CT vs. TT).</p

Distribution of <i>CTLA-4</i> genotype among patients and controls included in the meta-analysis.

a<p>AA or CC;</p>b<p>AG, CT, or AC;</p>c<p>GG, TT or CC.</p><p>HWE, Hardy-Weinberg equilibrium.</p

Funnel plot for publication bias in selection of studies on the <i>CTLA-4</i> +49 A/G polymorphism (AA vs. AG+GG).

<p>Funnel plot for publication bias in selection of studies on the <i>CTLA-4</i> +49 A/G polymorphism (AA vs. AG+GG).</p

Determination of the genetic effects of <i>CTLA-4</i> polymorphisms on asthma and sensitivity analyses.

<p>vs., versus; R, random-effects model.</p

Determination of the genetic effects of <i>IL4RA</i> polymorphisms on asthma and subgroup analysis.

<p>Bonferroni correction was applied (<i>P</i><0.00714). vs., versus; R, random-effects model; F, fixed-effects model; HWE, Hardy-Weinberg equilibrium.</p

Characteristics of the case-control studies included in meta-analysis.

*<p>Different data could be separately extracted.</p><p>NA, not available.</p