We next applied PPI networks with the premise that genes that are more central in the network or have more connections to other genes are more essential than less connected ones. We found significantly higher connectivity for large-effect cis-eQTL genes in the family than for cis-eQTL genes in the population (Figure 3B). Furthermore, this contrast became stronger when we focused only on those genes that also contained a proximal rare and potentially regulatory variant (Figure 3B).