DDR2 and neoplasm: In contrast, we found that only +DDR2/+COL1 tumours showed significantly higher levels of pAKT-S473 (Supplementary Fig. 7C,D), compared to −DDR2/+COL1 tumours, suggesting that AKT-mediated signalling plays a role in the stimulation of tumour growth in the +DDR2/+COL1 xenografts.