XIRP2 and familial dilated cardiomyopathy: The expression levels of many central genes encoding Z-disk structural proteins were significantly down-regulated in DCM patients with TTNtv compared to healthy donors: FLNC (filamin-C; 4.7-fold decrease), MYOT (myotilin; 18.1-fold), PALLD (palladin; 1.9-fold), XIRP2 (xin actin-binding repeat containing 2; 6.7-fold), ZYX (zyxin; 2.2-fold), CRYAB (α-crystallin B chain; 3.2-fold), MYOZ1 (myozenin-1; 2.3-fold), and LMCD1 (LIM and cysteine-rich domains 1; 18-fold).