The expression of PEPP2 was not observed in other types of cancer cell lines including U87MG, T98G, A147 (brain tumor), LU99, EBC1, A549 (lung cancer), PK59, PK1, PK8 (pancreatic cancer), KU7 (bladder cancer), JCA1 (prostate cancer), HSS78 (breast cancer), MDA231 (renal cancer), and 501Amel (melanoma). This evidence concerns the gene RHOXF2 and breast cancer.