BAG3 and myopathy: Interestingly, the cochaperone BAG3 (discussed below in more detail) was implicated in the pathomechanism of DNAJB6 mutations by the finding that the coexpression of wild-type BAG3 but not the myopathy-linked p.P209L mutant exacerbated the toxicity of mutant DNAJB6b in zebrafish [14].