In contrast homozygous hSOD1D90A/D90A mice form a distinct strain B in addition to A. Inoculation of strain A or B aggregate preparations into the spinal cords of adult mice expressing a hSOD1 transgene induced templated hSOD1 aggregations spreading concomitantly with premature fatal motor neuron disease [12]. The gene discussed is SOD1; the disease is motor neuron disorder.