Hi all! While looking for eQTL data from brain tissues to do a colocalization analysis to study Alzheimer's disease I found this great article: https://www.nature.com/articles/s41398-018-0150-6 They talk about the two sets of eQTL summary data that they used (one with adjustments and another with more adjustments): """ **Summary data-based Mendelian randomisation** To test for pleiotropic associations between SNPs and AD and gene expression/DNA methylation in the brain, summary data-based Mendelian randomisation (SMR) was performed17. GWAS summary output from the meta-analysis of UK Biobank and IGAP (sample size specified as 314,278?+?74,046?=?388,324) were included along with expression Quantitative Trait Loci (QTL) summary output from the Common Mind Consortium, which contains data on **>600 dorsolateral prefrontal cortex** samples, and DNA methylation QTL summary output on **258 prefrontal cortex** samples (age >13)[18]. The reference genotypes were based on the Health and Retirement Study, imputed to the 1000 Genomes phase 1 reference panel. SNP exclusions included: imputation score <0.3, Hardy?Weinberg P-value 600 samples," but in the dataset [syn4622659](https://www.synapse.org/#!Synapse:syn4622659), they say that the Gene-level eQTL (and isoQTL) were derived from: "**n=467** genetically-inferred Caucasian samples (209 SCZ cases, 206 Controls, and 52 AFF cases)". I need to know the sample size, so I would be grateful if someone could clarify this, please. Also, I wanted to know if the eQTL data is based on the reference genome Hg38? I want to use it for colocalization analysis and need to know if I should apply liftover. I'll very gratefull for your help. Kind regards :)