BEST1 and dry age related macular degeneration: Notably, iPRE cells were found to express two variants of PHOSPHO1, as validated by real‐time quantitative PCR (qRT‐PCR) and Western blotting (Figure 3E–G), and an analysis of previously published gene microarray data[26] indicated that compared with the positive control BEST1 gene, the expression level of PHOSPHO1 is extremely low, almost non‐existent, and there is no difference in the RPE/choroid of normal individuals, dry AMD, and wet AMD patients (Figure S5, Supporting Information).