HSPB7 and maternally-inherited diabetes and deafness: HSPB7 (Heat Shock Protein Family B member 7), a heat shock protein highly expressed in cardiac tissue, showed a trend for increased gene expression in mutant cells of both patients (Figure 5d), as did the HSF1 gene (Heat Shock Factor 1), a regulator of the unfolded protein response, and this was significant in the MIDD patient (Figure 5d).