The causal mechanisms by which the effects of genetic variants are cascaded through has been at the forefront of current quantitative genetics research. This involves understanding how genetic variants regulate intermediate molecular phenotypes like gene expressions, proteins, metabolites etc., and how they interact with each other to form a complex network ultimately bringing about change in the trait. Currently, the research in this domain is restricted to understanding the mediating effect of a single gene or protein on the outcome. However, since proteomic and transcriptomic studies are getting larger and are making data publicly available, one of current research focuses is to construct causal networks which approximates the mechanisms by which the effect of a genetic variant is mediated to the trait. Thus, research in this domain can provide a wholesome view of the underlying genetic composition of a trait and can inform therapeutic targets. Naturally, this would synergize different domains of existing research like co-expression, construction of large DAGs, mendelian randomization and inspire novel techniques of graph-based estimation. The work is currently under progress.