PTCH1 and stroke disorder: PTCH1 is involved in sonic hedgehog signaling, a pathway that for instance reduces oxidative stress on neurons and regulates ischemia-induced neuronal progenitor proliferation.33,34 In rats with experimentally induced middle cerebral artery occlusion, inhibition of the sonic hedgehog signaling caused increased infarct size, and PTCH1 was downregulated when sonic hedgehog signaling was inhibited.20,35 The association between PTCH1 and stroke outcome observed in the present study may thus potentially be explained by an increased infarct size.