Compared to mosaically introduced RasG12V cells in normal skin, those in doxorubicin-treated skin relatively strongly expressed cdkn2a/b, il1b, 1l11b, and ROS (Fig. 6d–g, Supplementary Fig. 12f) and efficiently induced tumour-like cell masses (Fig. 6h). This evidence concerns the gene IL1B and neoplasm.