COL4A3 and Hypertension: However, previous studies have shown that both adenine-fed mice and Col4a3−/− mice develop hypertension.43,45,69,70 Importantly, cardiac-specific FGFR4 knockout mice and 5/6 nephrectomized rats treated with an FGFR4 blocking antibody exhibit protection against cardiac remodeling despite developing elevated blood pressure.27