Effect of Calcitriol in Inhibiting the Cancer Cell Growth and Promoting Apoptosis in ErbB2-positive Breast Cancer Cells.

Background: Targeted therapies, specifically ErbB family tyrosine kinase inhibitors, have demonstrated potential for improving outcomes in patients with ErbB2-positive breast cancer. Despite their effectiveness, these therapies are associated with limitations, including high costs, side effects, drug resistance, lack of specificity, and toxicity. To overcome these challenges, drug repurposing has emerged as a promising strategy in breast cancer treatment.