Immortalized human embryonic kidney cells (HEK293FT) and cervical cancer (HeLa) cells stably expressing eGFP-Smad5 were cultured in medium with variable adjusted pHe (pH 6.0, pH 6.4, pH 6.8, pH 7.2, pH 7.6, and pH 8.0). The gene discussed is SMAD5; the disease is cervical carcinoma.