PTK2 and Atrophy: Compared to healthy-iRPE, L-ORD-iRPE upregulated 53/84 genes (>4-fold) associated with dedifferentiation (e.g., ESR1, PDGFRB, TMEFF1, KRT14, PTK2, SOX10, GSK3B, TSPAN13, WNT5a, GNG11, ITGAV, SNAI3, and MMP9) following 1 week of daily POS feeding, suggesting a possible mechanism of RPE atrophy and L-ORD disease phenotype worsening due to life-long POS uptake by diseased patient RPE cells.