For instance, the action of microRNAs (miRNAs)—small, single-stranded RNA sequences which function as posttranscriptional regulators of gene expression—on PTEN inactivation has been recently described, with the characterization of miR-22 and miR-106b~25 as PTEN-targeting miRNAs aberrantly expressed in PCa [89]. The gene discussed is PTEN; the disease is posterior cortical atrophy.