Furthermore, the activity of the combination of cetuximab with palbociclib was evaluated in a cetuximab-sensitive CRC PDTX model with wild-type Kirsten rat sarcoma 2 viral oncogene homolog (KRAS)/Neuroblastoma RAS viral oncogene homolog (NRAS)/b-raf proto-oncogene serine/threonine kinase (BRAF) but, similarly to our findings, they did not observe a statistically significant benefit when cetuximab was combined with a CDK4/6 inhibitor, as compared to cetuximab monotherapy [50]. This evidence concerns the gene CDK4 and colorectal carcinoma.