The isolated outer cornea cultured in presence of acidic Fibrob‐last Growth Factor (aFGF) can reprogramme its differentiation into lens fibres. The capacity of aFGF to promote lens differentiation is not linked to its mitogenic activity. In previous studies (Boscoet al.,1997) it was observed that the lens transdifferentiation of corneal cells occurs also when DNA replication and cell proliferation are prevented by addition of aphidicolin (a specific inhibitor of DNA polymerase in eukaryotes), to the culture medium. Experiments in which either transcription or translation have been inhibited by actinomycin D and cycloheximide, respectively, have now shown that the corneal cells are unable to transdiffer‐entiate into lens fibres. These results indicate that the multi‐step process lens‐transdifferentiation of corneal cells can be controlled also at these levels.