In our study, a 549 bp product of FAP-α could be amplified in both MCF7exp and MDA-MB-231exp cells while the western-blotting assay of FAP-α protein expression in breast cancer cells showed that a 30 kDa truncate was detected instead of the 97 kDa monomer and 170 kDa dimer. The gene discussed is FAP; the disease is breast cancer.