PRB2 and breast cancer: Down-regulated sample (CP7) of Tp53 gene were‏ found heterozygous at 105G>G/A in exon 3,‏ 465T>T/C in exon 4 and 1050G>G/A in exon 9 loci,‏ which are homozygous (A), (T) and (G) in up-regulated‏ samples of the mammary tumors respectively.‏ These loci 202C/G, 769C, 278G, 1474T/C, 1555C,‏ 2737G/A, 2941G/A of (CP7) are different from the‏ above mentioned up-regulated samples (Table 3).