We apply DS algorithms to the human PPI network [28] and measure the size of the resulting DSs, as well as their enrichments in BC and SP genes. We find that: (1) the enrichments in BC and SP genes of nodes of DSs are much higher than the enrichments of nodes outside of DSs; (2) the enrichments in BC and SP genes of nodes of DSs are statistically significant, while those of nodes outside of DSs are not; and (3) BC and SP genes that are in DSs have much higher and statistically significant enrichments in known drug targets than BC and SP genes that are not in DSs. Hence, we confirm our hypothesis that DSs capture biologically vital proteins and also drug targets.