Sample size and tissue matching contribute to accuracy of transcriptomic imputation results. Our CMC-derived DLPFC prediction models had higher average validation R2 values in external DLPFC data than GTEx-derived brain tissue models. Notably, the model with the second highest percent of genes passing the R2 threshold is the Thyroid, which has the largest sample size among the GTEx brain prediction models. When looking at mean R2 values, the second highest value comes from the GTEx Frontal Cortex, despite the associated small sample size, implying at least some degree of tissue specificity of eQTLs architecture.
