Interestingly, an E2F1-independent tumor suppression effect of phosphorylated RB has been unveiled by Jin et al. (336), and it is said that CDK4/6 mediated phosphorylation of RB at S249/T252 enhances its interaction with NF-κB p65 within nucleus and reduces the expression of NF-κB target genes, including PD-L1. This evidence concerns the gene E2F1 and neoplasm.