Special issue on 'Genetic epidemiology of complex diseases: impact of population history and modelling assumptions'.

The conduct of genetic epidemiological research on complex diseases has massively changed during the past decades, shifting from candidate-gene studies via array-based genome-wide association studies (GWAS) to sequencing approaches. Liu and Montgomery ([6]) in their review give an overview on the timely topic of using cell type information as a follow-up to GWAS studies. She concludes that missing heritability is an ill-posed problem, because heritability is defined through an oversimplified model that does not fit the underlying complex biological structure. Evolutionary perspectives on polygenic selection, missing heritability, and GWAS. [Extracted from the article]