Phospho-BRAF(Thr401) Antibody (YA5912)

B-Raf is a serine/threonine protein kinase encoded by BRAF and functions as a central signal transducer in the RAS-RAF-MEK-ERK signaling cascade that regulates cell proliferation, differentiation, and survival^[1][2]. Mechanistically, activated B-Raf phosphorylates MEK, leading to ERK activation and propagation of mitogenic signaling, making B-Raf a critical regulator of MAPK pathway output^[2]. Dysregulation of this pathway is strongly linked to oncogenesis, and somatic BRAF mutations are among the most common kinase alterations identified in human cancer, particularly melanoma, colorectal cancer, thyroid cancer, and non-small-cell lung cancer^[1][3]. In disease models, the canonical BRAF V600E mutation constitutively activates kinase signaling and promotes tumor cell growth independent of normal upstream regulatory inputs^[2][3]. Compared with the related RAF isoforms A-Raf and C-Raf (RAF1), B-Raf displays stronger basal kinase activity and is the most potent activator of MEK-ERK signaling, making it a dominant MAPK pathway driver in many BRAF-mutant tumors^[2]. For experimental applications, selective B-Raf inhibitors have been widely used to suppress oncogenic MAPK signaling and to investigate pathway dependence in cancer models^[4]. The development of mutation-selective inhibitors, including compounds targeting BRAF V600E, established B-Raf as a validated therapeutic and mechanistic target and continues to support research on signaling regulation, drug resistance, and combination treatment strategies^[4][5].