CDK8 and non-small cell lung carcinoma: To understand the significance of RFC4-induced stabilization of NICD1 in promoting NSCLC metastasis and stemness properties, an NICD1 mutant (NICD1mut) plasmid was employed that expresses an NICD1 protein constantly stabilized due to its ability to resist CDK8-mediated phosphorylation and thus leads to sustained activation of Notch signaling18.