Source:http://linkedlifedata.com/resource/umls/id/C1510411
NCI: In medicine, the change that a normal cell undergoes as it becomes malignant.,NCI: The conversion of a cell from a normal phenotype, which undergoes a limited number of mitotic divisions, into an aberrant phenotype that is immortal and divides indefinitely. Transformed cells no longer retain cell-cycle checkpoints and may ultimately become malignant cancer cells via additional genetic mutations, or damaging environmental events.