MC3T3 is an osteoblast precursor cell line derived from Mus musculus (mouse) calvaria. MC3T3 is an osteoblast precursor cell line derived from Mus musculus (mouse) calvaria. A number of derivatives of this strain have been isolated to select for varying degrees of osteogenic potential, and have been widely used as model systems in bone biology. A standard textbook calls its MC3T3-E1 sub-line 'one of the most convenient and physiologically relevant systems for study of transcriptional control in calvarial osteoblasts.'