The tumor formation frequency for ALDH+ cells (1 in 2 × 104) from both xenografts was estimated to be 5- and 21-fold that of ALDH- cells ( 1 in 1.1 × 105 and 1 in >4.2 × 105) for BC-P007 and BC-P515, respectively, as shown in Table 2. The gene discussed is LDHA; the disease is breast cancer.