While tumour disease did alter total STAT3 protein levels in WT mice, the ratio of phosphorylated STAT3 to total STAT3 was higher in tumour diseased CKO mice, suggesting that non-cardiomyocytes display a higher STAT3 activation state compared with WT B16F10-TM (Fig. 2B–E). Here, STAT3 is linked to neoplasm.