HES1 and small cell lung carcinoma: Notch pathway is one of them, Notch1 is crucial in cell survival, abnormal expression of Notch1 has been considered as a universal phenomenon in small cell lung cancer.34 NF‐E2‐related factor 2 can activate Notch1 and regulate the proliferation of haematopoietic progenitor cells (HPCs).35 The results are consistent with our findings that inhibition of Notch1 lowered the expression of its target genes HES‐1 and inhibited the tumour proliferation.