It was demonstrated that D-glucuronyl C5-epimerase ectopic expression did not influence the viability of breast cancer cells MCF7 in Colony Formation Test - the number of epi-MCF7 colonies per 10 mm plate was even higher than those on the plates with MCF7 and pCEP4-MCF7 cells (Fig.2A). The gene discussed is GLCE; the disease is breast cancer.