In an ELISA assay, employing the 196X mAb, the combined mean level of factor H and FHL-1 was higher in the cancer patient AF (758±312 μg ml−1, mean±s.d.; n=16) than in NHS (461±63 μg ml−1, n=8; Student's t-test, P<0.05) or in AF samples from liver cirrhosis patients (43±27 μg ml−1, n=6). This evidence concerns the gene CFH and atrial fibrillation.