GUCY1B1 and neoplasm: It is also notable that MYC cooperates with NOTCH to drive subtype switching from NE to Non-NE12,24 and that like MYC10, GUCY1B1 is expressed in the Non-NE subpopulation of CDX17P, suggesting that the minority population of Non-NE cells in the tumour is responsible for etoposide resistance during disease evolution.