Furthermore, mice injected withDOT1L+HRAS MCF10A cells exhibited more prominent tumour growth.Notably, histological analysis showed that DOT1L induced more poorlydifferentiated invasive ductal carcinomas compared with those induced by HRAS,and co-expression of DOT1L and HRAS resulted in more aggressive, high-gradeinvasive tumours with low E-cadherin expression (Fig. 2f),implying the additive effect of DOT1L and HRAS on breast tumorigenesis. Here, DOT1L is linked to invasive ductal breast carcinoma.