WWP1 and breast cancer: Although Peschiarroli A et al. reported that WWP1 mediates Lys63-linked ubiquitination of ΔNp63and regulates ΔNp63-dependent transcription but not its proteasomal degradation in primary human keratynocytes [28], evidence from Li Y et al. shows that in some breast cancer cell lines, particularly under DNA damage conditions, WWP1 can mediate proteasomal degradation of ΔNp63α [20].