Discovery proteomics with O-Link reveals new HCC markers?

When I think of proximity extension assays (PEA) which is either famous because of O-Link - or is? O-Link, I think of purely using it for large population studies or for validating discoveries by high depth mass spectrometry based proteomics. But...could you use it in place of mass spec proteomics? Because that is basically what this group did here. Now...if your protein or proteoform isn't in…