If 3D spheroid size and stiffness were mainly related with network-forming COL4 and fibril forming COL1, then the PG- or OMD-induced down-regulation of COL6, FN, and αSMA would result in a relative increase in COL1 content, which provides a possible explanation for why PG or OMD caused changes in both the size and stiffness of the 3D spheroids. This evidence concerns the gene FN1 and occult macular dystrophy.