*Initially described in [[bone marrow]].<ref>{{Cite journal | last1 = HARGRAVES | first1 = MM. | last2 = RICHMOND | first2 = H. | last3 = MORTON | first3 = R. | title = Presentation of two bone marrow elements; the tart cell and the L.E. cell. | journal = Proc Staff Meet Mayo Clin | volume = 23 | issue = 2 | pages = 25-8 | month = Jan | year = 1948 | doi = | PMID = 18921142 }}</ref>