Although the lack of an appropriate antibody for the specific immunohistochemical detection of serine 207 residue in FOXO3 phosphorylated by MST1 kinaseprevented the detection of FoxO3 activity modified by MST1, these results, coupled with the results of in vitro assays, suggest that BRAFV600E may alleviate the tumor suppressor function of RASSF1A-MST1 and vice versa. The gene discussed is FOXO3; the disease is neoplasm.