Abstract: The present invention relates to lung cells having a novel phenotype, morphology, and immunoprotectant properties. The invention further relates to cell lines derived from such cells and methods for producing such cells, both in vivo and in vitro. The invention additionally relates to expression products of such cells and cell lines. The present invention also relates to the application methods that temporarily ameliorate CFTR deficiency to in utero therapy, with the surprising result that amelioration then extends beyond birth and beyond the duration of the temporary in utero effect to become long-lasting amelioration.