GSK3B and chronic myelogenous leukemia, BCR-ABL1 positive: To establish a correlation between the effect of celecoxib on β-catenin protein stability and on proliferation/colony formation of Ph+ CML cells, we generated a LAMA-84 parental cell line expressing a constitutively active mutant form of β-catenin (β-catenin S33Y) that cannot be targeted to the proteasome because it is not phosphorylated by GSK3β [25,26].