PCNA and Schnyder corneal dystrophy: Given that increased SOX9, an ER-regulated gene [41,42], was found in FliiTg/Tg epidermis when compared to Flii+/− and WT counterparts, while Flii is an estrogen receptor coactivator, it is possible that elevated nuclear Flii promotes increased SOX9 at the transcriptional level which may also explain the increased number of PCNA+ cells observed in FliiTg/Tg embryonic mice skin secondary to increased SOX9 signalling that drives increased SCD.