The constitutional heterozygosity for the DNF15S2 locus and for one allele of the c-erbA beta and the c-raf-1 proto-oncogenes was lost in nonpapillary RCCs, whereas both alleles were retained in each papillary RCC analyzed.
The c-raf-1 oncogene is located at chromosome 3p25, near a region known to be specifically deleted in patients with renal cell carcinoma and small cell lung carcinoma (SCLC).