CXCR4 rs2228014 (C/T) genetic polymorphism. (a) Electrophoretic profile of rs2228014 (C/T). BccI restriction enzyme was used for 4 h at 37°C. Polyacrylamide gel 10% stained with silver nitrate. Lane 1, Ladder DNA fragment marker of 100 bp; Lane 2, PCR product of 236 pb; Lane 3, wild-type homozygous genotype of 133 pb and 103 pb (CC); Lane 4, heterozygous genotype of 236 pb, 133 pb, and 103 pb (CT); Lane 5, blank reaction or negative control (reaction without DNA). (b) Genotype distribution for CXCR4 rs2228014 in breast cancer patients.