PTEN and neoplasm: In human B‐cell lymphomas, miR‐19 promotes tumour cell survival by inhibiting PTEN directly and activating AKT/mTOR pathway.22 Expression of miR‐19 is elevated in SHH medulloblastoma, a subgroup of medulloblastoma characeterized as constitutive activation of the Sonic Hedgehog pathway, anti‐miR‐19 treatment restrains proliferation of tumour cells and prolongs survival of tumour‐bearing mice23 (Figure 1).