Functional annotation of the identified proteins using enrichment of biological pathways and gene ontology (GO) terms in DAVID (Panel A: TOP - antigen presentation cluster, BOTTOM - metabolism cluster). Green block indicated that a particular gene (columns) that is associated with a given pathway/GO term (rows) was identified in the secretome (BT-474 - red, SKBR3 - black, both cell lines - blue). Black regions of the grid indicate that GO association for a gene has not been reported. Graphical summaries of the MHC class I pathway (Panel B) and the glycolysis/gluconeogenesis pathway (Panel C) obtained from the KEGG Pathway database were annotated with the identified proteins (BT-474 secretome - red star, SKBR3 secretome - black star, secretomes from both cell lines - blue star).