Zhang and colleagues [70] showed that miR-21 induced growth and invasion in non-small cell lung cancer by repressing PTEN (phosphatase and tensin homolog); moreover, miR-21 modulate TRAIL sensitivity in glioma cells mainly by modulating caspase-3 and TAp63 expression and TRAIL-induced caspase machinery [71], confirming that miR-21 acts like an oncogene by blocking the expression of critical apoptosis-related genes. The gene discussed is PTEN; the disease is central nervous system cancer.