Although the effector domain of MARCKS, also called the phosphorylation site domain, has, once it is phosphorylated, been reported to mediate the association of the MARCKS protein with other cellular components leading to altered cellular functions [24,26,27], siRNA silencing of MARCKS does not determine if it is the total expression of MARCKS or its phosphorylation that is essential for WNT5A-induced melanoma cell invasion. The gene discussed is WNT5A; the disease is melanoma.