Localization of the mcf.2 transforming sequence to the X chromosome.

Abstract
A transforming sequence was identified using co‐transfection of DNA from the human mammary carcinoma cell line MCF‐7 and of a G418 resistance gene into NIH 3T3 cells, followed by tumor formation in athymic mice. This sequence, named mcf.2, was molecularly cloned. A transforming activity resides in a cosmid clone of 42 kb. mcf.2 did not cross‐hybridize with the known oncogenes tested. In situ hybridization localized it on the X chromosome, probably at q27. This localization was confirmed by hybridization to a panel of human–rodent cell line DNAs.