Sex-biased genes involved in vascularization
In line with our prediction that males would exhibit increased expression of genes associated with vascularization, we found that genes more highly expressed in males were enriched for biological processes associated with angiogenesis (K-S Test: D=0.19,P =7.25x10-7; Fig. 4 ). Additionally, these genes in males were also enriched for biological processes associated with blood pressure regulation and blood vessel maintenance (K-S Test: D=0.19, P =2.59x10-5; Fig. S5 ). Contrary to our predictions, we did not find evidence for increased expression of genes associated with estrogen or androgen regulation in males – including no evidence for indirect effects through protein-protein networks: there was no enrichment for genes involved in PPI networks for ER\(\alpha\) (K-S Test: D=0.04,P =0.07), ER\(\beta\) (K-S Test: D=0.05, P =0.17), or AR (K-S Test: D=0.04, P =0.46). For subset of individuals for which we had matched skin biopsies and chest redness at baseline while under anesthesia (n =10 males, n =8 females), we did not find a correlation between the average standardized expression level of genes involved in PPI networks for ER\(\alpha\), ER\(\beta\), or AR and chest redness within males or within females (Fig. S6).