Based on our previous results that the combination of an IL‐6 Ab and Box5 reduced both Cdc42‐GTPase activity and the invasive migration of BRAFi‐R melanoma cells, we next investigated whether inhibition of Cdc42‐GTPase activity could affect the level of filamentous actin (F‐actin) in these resistant cells and thus explain their impaired invasive migration. Here, CDC42 is linked to melanoma.