Immunohistochemistry (IHC) for MSX1, RYK, NFκB p65, and CCL4 proteins and chromogenic in situ hybridization (CISH) for MSX2, RYK, and PTX3 genes were used to analyze postnatal human cleft lip tissue (15 patients) and control tissue (6 patients). The gene discussed is MSX2; the disease is cleft lip.