NFKB1 and breast cancer: Studies have revealed a negative effect of β-catenin on NF-κB activity in liver, breast, and colon cancer cells.402,403 Leucine zipper tumor suppressor 2 (LZTS2) is a putative tumor suppressor, and NF-κB activation inhibits β-catenin/TCF activity through upregulation of LZTS2 in liver, colon, and breast cancer cells.404–406 Wnt/β-catenin and Hh signaling have important functions in embryogenesis, stem cell maintenance, and tumorigenesis.