MAP2K1. also known as MEK1. is a dual-specificity kinase within the MAPK/ERK signaling pathway, playing a critical role in regulating cell proliferation, differentiation, and survival. It activates downstream ERK1/2 through phosphorylation of specific tyrosine and threonine residues. MAP2K1 antibodies are essential tools for studying this pathway's activity and dysregulation in diseases like cancer, where mutations (e.g., Q56P, K57N) drive uncontrolled cell growth. These antibodies are widely used in techniques such as Western blotting, immunohistochemistry (IHC), and immunofluorescence (IF) to detect MAP2K1 expression, phosphorylation status, or mutation-specific variants. Researchers often pair them with phospho-specific ERK antibodies to assess pathway activation. Commercially available MAP2K1 antibodies typically target epitopes within the N-terminal regulatory domain or the C-terminal kinase domain (UniProt: Q02750). Validation includes testing in knockout cell lines or tissues to confirm specificity. In clinical research, MAP2K1 antibodies help identify patients with MEK-inhibitor-sensitive mutations (e.g., in melanoma or NSCLC) and monitor therapeutic responses. Proper controls, such as phosphorylation status verification or mutation-specific blocking peptides, are crucial for experimental accuracy due to pathway cross-talk and homologous sequences in MEK2.