DICER knockdown in GSCs resulted in widespread down-regulation of cellular miRNAs, the majority of which were tumor suppressor miRNAs, such as let-7a and let-7b; however, not all miRNAs were reduced to the same extent and this is likely due to the fact that each step of the general miRNA biogenesis pathway differentially fine-tunes miRNA expression. The gene discussed is DICER1; the disease is neoplasm.