IBSP and atrial fibrillation: In addition, the mRNA expression of both integrin-binding sialoprotein (IBSP) (ratio degenerative vs. non-degenerative 0.062 ± 0.026; p < 0.01) and B-cell scaffold protein with ankyrin repeats 1 (BANK1) (0.370 ± 0.070; p < 0.05) were markedly decreased in degenerative AF.