More recently, knocking down EEF1A2 expression in zebrafish, using translation blocking and splice-site interfering morpholinos, showed that EEF1A2 deficiency in this species leads to skeletal muscle weakness, cardiac failure and small heads, a morphant phenotype that could be rescued by the use of human EEF1A2 wild-type mRNA, but not mutant RNA [90]. The gene discussed is EEF1A2; the disease is heart failure.