Given the topologically central role of nodes in a DS, we apply to the human PPI network an existing DS algorithm that is commonly used in telecommunications, with the hypothesis that a DS might capture a set of proteins in a PPI network that are involved in important biological processes and mechanisms crucial for cell vitality. Also, we design a new and simpler DS algorithm that outperforms the existing algorithm on our data. We emphasize that our main focus is not to create a state-of-the-art algorithm for finding DSs, but instead, to demonstrate, as a proof of concept, that a DS of a PPI network found by a very simple algorithm captures biologically vital proteins. Indeed, we find that: (1) the enrichments in BC and SP genes are much higher for nodes of DSs than for nodes outside of DSs; (2) the observed enrichments are statistically significant for nodes of DSs, while for nodes outside of DSs they are not; (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; and (4) GDC-central genes that are also in the DS contain the highest, statistically significant percentage of drug targets.