XBP1 and heart failure: Here, we considered that the category containing 77 genes (dark pink) was most important in understanding how the constitutive expression of XBP1(S) rescued the heart failure observed in KO medaka, as their expression levels were significantly increased (69 genes) or decreased (eight genes) in KO medaka compared with WT medaka, but significantly decreased (69 genes) or increased (eight genes) in [KO + XBP1(S)] medaka compared with KO medaka.