By using ALDEFLUOR assay for detecting ALDH expression followed by standard FACS analysis, we successfully isolated ALDHbr cells and found that SAHA can suppress the growth of tumor xenografts and decreases the lung CSC population in vivo. Surprisingly, we found that residual ALDHbr cells from SAHA-treated mice exhibited properties of cancer stem cells, including high capacity of tumorigenesis, metastasis and stem cell-related gene expression. Here, LDHA is linked to neoplasm.