A progenitor cell with the potential to differentiate into luminal epithelial cells of mammary glands. In mouse, CD61 and c-kit were found to be coexpressed by the majority of, but not all, committed luminal progenitor cells. [ https://orcid.org/0000-0003-4412-7970 http://www.ncbi.nlm.nih.gov/pubmed/19063729 http://www.ncbi.nlm.nih.gov/pubmed/20346151 http://www.ncbi.nlm.nih.gov/pubmed/21930782 ]