In addition, publically available external datasets imported from Gene Expression Omnibus were compared, including the datasets of keratinocytes [33], cervical cancer cell line ME180 overexpressing basal cell-associated transcription factor p63 [34], a CD44+CD24- stem/progenitor-like immortalized breast epithelial cell [35], basal-like breast carcinoma [36] and skin and lung fibroblasts [37]. Here, CD44 is linked to breast carcinoma.