Although this result is currently a matter of controversy, further studies must be independently repeated to be conclusive; -- another RFLP was found in c-mos proto-oncogene, which is detected only in patients with breast cancers or other types of tumors.
In the case of Ha-MSV-containing constructs stably integrated in the two human breast cancer lines, however, CAT expression was more than two orders of magnitude greater than that transiently expressed in these cells.
The 5-kb allele of the MOS oncogene, previously proposed to be associated with breast cancer, was absent in these families, suggesting that polymorphism at this locus is not associated with inherited susceptibility.