To determine a role for BCL9/9l in colonic tumour growth we injected 4-hydroxy tamoxifen into the colonic submucosa of VillinCreERApcfl/fl and VillinCreERApcfl/flBcl9fl/flBcl9lfl/fl mice to induce local recombination40. The gene discussed is BCL9; the disease is colonic neoplasm.