In addition, subgroup analysis by different cut-off class also presented with several interesting discovers, which showed correlation of high ALDH expression with poor OS and DFS/PFS when studies set the cut off class as low expression, but not high expression in ovarian cancer patients, which implied that ALDH expression existed in a small subpopulation of cancer cells, and we guessed when the cut-off class is defined as high expression of ALDH, most of ovarian cancer patients with intermediate ALDH expression are excluded and assigned to low expression group. The gene discussed is LDHA; the disease is ovarian cancer.