NDRG1 and neoplasm: M1-3 had similar human tumour marker expression but diverse oncogenic signalling activation patterns, with OSAhigh M1 and M3 showing distinctive signalling: M1 had low p-Akt and p-NDRG1 and high p-p38 and M3 had high PI3K/mTOR effectors and high p-ERK (Fig. 3a).