The ability of systemic Ivermectin to also block lung cancer growthin vivo supports the possible use of Ivermectin in particular, and other macrocyclic lactones such as Selamectin in general, as WNT-TCF pathway response blockers to combat WNT-TCF-dependent human diseases including cancers of the intestine, breast, skin, and lung. This evidence concerns the gene HNF4A and lung cancer.