We found the microRNA, miR-34a, was expressed at twice the level in CD44+ prostate cancer cells purified from xenograft tumors (LAPC4 cells) compared to CD44- LAPC4 cells, whereas the original study reported miR-34a was underexpressed in CD44+ LAPC4 cells (Figure 1B; Liu et al., 2011). Here, CD44 is linked to prostate carcinoma.