NOTCH1 and non-small cell lung carcinoma: The authors identified a positive feedback loop that regulates the Notch1-RFC4 axis, where RFC4 amplifications and Notch1-mediated RFC4 upregulation can in turn prevent the degradation of NICD1 by CDK8/FBXW7 further leading to NSCLC metastasis (Liu et al., 2021).