A remarkable study by Hanna et al. [36], utilizing NanoString Immune Gene Expression Analysis to compare the immunoprofile of PVL and OL, found a significantly higher expression of CD8+ T cells, T regs as well as PD-L1 in PVL and proposed the immunotherapy targeting the PD-1/PD-L1 pathway might be of therapeutic benefit in PVL. The gene discussed is CD8A; the disease is periventricular leukomalacia.