While mice overexpressing a truncated constitutively active HSF1 under the control of a human β-actin promoter fail to overexpress HSF1 in the CNS and the male transgenic mice are infertile,38,39 our HSF1-Tg mice grow and breed normally as WT mice, and exhibit moderate increase in HSF1 mRNA and protein expression in all tissues including the CNS6 and the retina (Fig. 2). The gene discussed is HSF1; the disease is Infertility.