The small membrane-associated G protein RAS and its relatives are signal transduction components connecting various classes of receptors (including RTK) to cytoplasmic pathways. Mutations of the GTPase onco-gene NRAS occur in about 15% of AML patients, KRAS mutations occur in fewer than 5% of cases, and HRAS mutations are rare. NRAS mutations (primarily point mutations in codons 12, 13, and 61) occur at specific positions that are critical for guanine triphosphate (GTP) hydrolysis, thereby preventing the conversion of the active RAS-GTP to the inactive RAS-GDP.

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