DKK3 and cancer: DKK‐3 is one of the DKK protein families and is known as a Wnt antagonist.41, 42 It is also recognized as a potential tumour suppressor, based on the facts that DKK‐3 expression is frequently down‐regulated in a wide array of malignancies.43, 44 Recent evidence indicates that DKK‐3 may also play additional roles in cancer cell survival.