RAF1 and breast cancer: Similar inhibition has been reported for other tissues and cells, such as AKT-induced phosphorylation of Raf-1 at Ser259 by insulin-like growth factor 1 in MCF-7, a human breast cancer cell line (Zimmermann and Moelling, 1999; Moelling et al., 2002) and by platelet-derived growth factor in vascular smooth muscle cells (Reusch et al., 2001).