PTK2 and neoplasm: Since LC-MS analysis was performed on whole-tumour extracts, in order to dissect metabolic alterations in different cell types and elucidate the cellular and molecular mechanisms that underlie how reduced expression of CAF-FAK could regulate the metabolism of malignant cells, we compared primary tumour cells from MMTV+;FSP-Cre−;FAKfl/fl and MMTV+;FSP-Cre+;FAKfl/fl mammary tumours by Seahorse Extracellular Flux analysis.