We showed that MTA1 ablation profoundly suppressed the growth of prostate tumors and the ability of tumor cells to colonize the bone by inhibiting their migratory and invasive properties through repression of cathepsin B (CTSB), a cysteine protease that plays a critical role in bone metastasis (Podgorski et al., 2005; Withana et al., 2012). Here, CTSB is linked to neoplasm.