Protein-proteininteractions(PPIs)havebeenwidelystudiedtounderstandthebiologicalprocessesormolecularfunctionsassociatedwithdifferentdiseasesystemslikecancer.Whilefocusedstudiesoninpidualcancershavegeneratedvaluableinformation,globalandcomparativeanalysisofdatasetsfromdifferentcancertypeshasnotbeendone.Inthiswork,wecarriedoutbioinformaticanalysisofPPIscorrespondingtodifferentiallyexpressedgenesfrommicroarraysofvarioustumortissues(belongingtobladder,colon,kidneyandthyroidcancers)andcomparedtheirassociatedbiologicalprocessesandmolecularfunctions(basedonGeneOntologyterms).Weidentifiedasetofprocessesorfunctionsthatarecommontoallthesecancers,aswellasthosethatarespecifictoonlyoneorpartialcancertypes.Similarly,proteininteractionnetworksinnucleicacidmetabolismwerecomparedtoidentifythecommon/specificclustersofproteinsacrossdifferentcancertypes.Ourresultsprovideabasisforfurtherexperimentalinvestigationstostudyproteininteractionnetworksassociatedwithcancer.Themethodologydevelopedinthisworkcanalsobeappliedtostudysimilardiseasesystems.