MAPK1 and fibrosarcoma: A-rapidly accelerated fibrosarcoma (A-Raf) is a serine/threonine protein kinase and a member of the Raf family of protein kinases, which consists of the A-Raf, B-Raf, and C-Raf isoforms [17], and regulates a variety of basic cellular functions, including proliferation, differentiation, transformation, apoptosis, and metabolism, mainly through the MEK/ERK pathway [18].