In PCa, the G2/M checkpoint can also be dysregulated directly by miRNAs following IR, for example miR-95 overexpression may enhance transit through the G2/M phase by targeting Sphingosine-1- phosphate phosphatase 1 (SGPP1 ) [40], which contributes to radioresistance. The gene discussed is SGPP1; the disease is posterior cortical atrophy.