IL6 and neoplasm: Because IL‐6 has been shown to activate STAT3 in Shh MB cells [33], and p‐STAT3 levels correlate with Shh signaling in other cancers [26, 34], to determine whether Shh signaling is associated with STAT3 in MB, we examined expression of p‐STAT3 and STAT3 in normal cerebellum and tumor tissue derived from SmoA1 mice, and each normal cerebellum and tumor tissue tested was from same adult mouse, which express constitutively activated Smo in cerebellar granule neuron precursors resulting in Shh MB [35].