AbstractThe cell of origin of cancer as well as cancer stem cells is still a mystery. In a recent issue of JCMM, Wang et al. challenged the conventional somatic genetic mutation model of multi‐stage carcinogenesis of breast cancer and proposed that ‘Invasive cancers are not necessary from preformed in situ tumours—an alternative way of carcinogenesis from misplaced stem cells’. If this stem cell misplacement theory could withstand future experimental evaluation, it may provide a paradigm shift in the prevention and management of cancer in the clinic.