SMN1 and cancer: Even though the present study has not investigated the cytotoxic effects, such as the proliferation & apoptosis in normal cell lines after prolonged exposure at 1 μM SMA concentration, we have assumed that the less cellular cytotoxic effects on cell proliferation by treatment of SMA are exhibited in the normal cell lines than those of cancer cell lines when compared with our earlier results, and probably that SMA could be considered as a selective anti-tumor drug for chemotherapy treatment.