Consistently, these rapidly growing tumours displayed loss of epidermal keratins K5/K10 and E-cadherin and gain of keratins K13, K8 and vimentin (Figure 7d; Supplementary Figure 11), changes typical of aggressive stages of skin carcinogenesis.34, 35 The abundance of γH2AX and the absence of lung metastasis (not shown) suggest that they are in an early stage of invasive conversion. This evidence concerns the gene KRT5 and neoplasm.