Results reflect GWAS scans for plasma levels of 44 cytokines or growth factors.

Cytokines were measured by using Bio-Rad’s premixed Bio-Plex Pro Human Cytokine 
27-plex Assay and 21-plex Assay, and Bio-Plex 200 reader with Bio-Plex 6.0 software.

The cytokine quantification was performed from EDTA plasma in FINRISK1997, 
from heparin plasma in FINRISK2002, and from serum in YFS.

Subjects whose cytokine concentration were below or above laboratory analysis detection 
limits were omitted from the analyses. Cytokine distributions were first normalized with 
inverse transformation. The transformed phenotypes were then adjusted for age, sex, body 
mass index, and the first ten genetic principal components by calculating residuals of 
linear regression model. Subsequently, another inverse transformation was performed for 
model residuals to ensure normally distributed phenotypes. All effect sizes are hereby 
in SD-scaled units.

Genome-wide association testing was performed using Snptest2 software v.2.5beta.
Meta-analyses were performed using METAL software (v.2011-03-25). Prior to meta-analysis, 
all markers with imputation info < 0.7, model fit info < 0.7, and minor allele count < 10 
were excluded. After filtering, 10.7 million markers were included in the meta-analysis. 
Each association test was weighted by sample size. Genomic control correction was used to 
account for population stratification and cryptic relatedness. Heterogeneity statistics 
based on Cochrane’s Q-test were calculated for all markers included in meta-analysis to 
estimate heterogeneity of effect sizes across the three cohorts.

see also: http://computationalmedicine.fi/data#Cytokine_GWAS

The data are made available as a collection of tab-separated, gzip-compressed text files. 

The size of each file is approximately 180MB.

The sample size and precision of the data presented should preclude de-identification of 
any individual subject. However, in downloading these data, you undertake not to attempt to 
de-identify individual subjects and to refer to the original publication.

The publication is:
Ahola-Olli AV et al.
Am J Hum Genet. 2017 Jan 5;100(1):40-50. doi: 10.1016/j.ajhg.2016.11.007. Epub 2016 Dec 15.
Genome-wide Association Study Identifies 27 Loci Influencing Concentrations of Circulating 
Cytokines and Growth Factors.