Two point mutations that result in an aspartate to alanine substitution at amino acid 67 and a glutamate to alanine substitution at amino acid 68 were introduced in exon 3 and a loxP flanked PGK-neomycin cassette was inserted upstream of exon 3. Cre-mediated recombination removed the neomycin cassette. These two mutations generate the PGF-DE variant seen in humans that results in the loss of binding and activation of FLT1 (VEGFR-1) but still maintains the ability to heterodimerize with VEGFA. (J:271257)