PIK3CA and familial dilated cardiomyopathy: These findings were confirmed by Western blotting, which revealed a significant increase of proteins expression in p-PI3K, p-AKT and p-mTOR in DCM+H19 group compared with those in the control group or DCM group (P < 0.05), consistent with decreased unfolded protein reaction (GRP78 and 94) as well as ERS (p-PERK, p-IRE1a, ATF6, CHOP) and apoptotic proteins (cleaved-caspase-3-9/-12 and Bax) tested by Western blotting (Figure 4C) or immuno- fluorescence staining (Figure 4B).