XBP1 and heart failure: Moreover, the time-course change in the ratio of miR-30a*/miR-214 during cardiac hypertrophy and heart failure (Additional file 1: Fig. S1) show that down-regulation of miR-30a* may minimize the role of increased miR-214 in regulation of XBP-1 in the early phase of cardiac hypertrophy, while increased expression of both miR-214 and miR-30* synergistically lead to suppression of XBP1 in the maladaptive heart.