Cylindrical injection of KCs alone with the 2-week culture yielded KRT13 or KRT14 expressing outermost bilayers analogous to that observed in KC-DP constructs with central necrosis in the KC compartment (data not shown), suggesting that the microenvironment by itself, putatively via extracellular matrix contact or nutrition, pH, and hypoxia gradient, could also play roles in the recapitulation of HF-like keratin distribution in KC-DP constructs. The gene discussed is CALCA; the disease is hydrops fetalis.