Secondly, in order to test whether the receptors for these chemokines, namely CCR1 and CCR2 (ref. 34), are involved in regulating cancer cell metabolism, malignant cells from MMTV+;FSP-Cre−;FAKfl/fl mice were exposed to WT-CAF CM, FAK-depleted CAF CM or FAK-depleted CAF CM with inhibitors to these receptors, CCR1i/CCR2i, or vehicle alone. Here, PTK2 is linked to cancer.