LDLRAP1 and neoplasm: Using ARH1-deficient MEFs transfected with the mutated ARH1 genes to measure of ARH1 function, different effects were seen with the different tumor-inducing gene mutations on proliferation, growth in soft agar and tumorigenesis in nude mice, suggesting that mutations in ARH1, in addition to effects on catalytic activity, could lead to conformational changes at the ARH1 active site, which alter other functions (for example, interaction with proteins).