RAF1 is a serine/threonine kinase that serves as a critical regulatory link between membrane-associated RAS GTPases and the MAPK/ERK signaling cascade, functioning as a molecular switch that determines cell fate decisions including proliferation, differentiation, and survival 1. The protein operates through sequential phosphorylation of downstream kinases MEK1/MEK2 and ERK1/ERK2, with its activity regulated by AMPK-mediated phosphorylation at specific residues like Ser621, which enhances binding to 14-3-3 scaffolding proteins 2. RAF1 also forms complexes with PPP1CB phosphatase and LZTR1, which regulate its phosphorylation state and activity 3. Disease relevance is significant, as RAF1 mutations cause RASopathies including Noonan syndrome, characterized by cardiac defects (particularly hypertrophic cardiomyopathy), short stature, and developmental delays 45. Clinically, RAF1-dependent signaling represents a therapeutic target, with MEK inhibition showing 89% response rates in histiocytic neoplasms regardless of genotype 6. RAF1 is also implicated in viral replication, pulmonary fibrosis through Dectin-1 signaling 7, and cancer metastasis via tumor-derived exosomes 8, highlighting its broad pathological significance beyond developmental disorders.