BRAF and breast cancer: Furthermore, neither #1181 nor 4EGI-1 impinge directly on the PI3-K Akt pathway that is activated in the MCF-7 and CRL-1500 breast cancer cells, or the B-raf/Erk pathway that is activated in CRL-2813 melanoma cell line, as demonstrated by the experiment depicted in Supplemental Figures S4A and S4B.