Forced expression of nuclear PHB increased the PHB‐involved HIRA complex‐facilitated H3.3 enrichment at the promoters of mesenchymal markers, such as N‐cadherin, vimentin, and fibronectin, and upregulated their gene expression levels through which nuclear PHB promoted the epithelial‐to‐mesenchymal transition (EMT) of breast cancer cells. The gene discussed is VIM; the disease is breast carcinoma.