M129 human PrP Drosophila (Fig. 4A) showed an enhanced accelerated decline in climbing ability in response to vCJD and classical BSE prions compared with the responses seen by the V129 human PrP fly line (Fig. 4B), although both fly lines showed a similar neurotoxic response to CWD prions. The gene discussed is PRNP; the disease is variant Creutzfeldt-Jakob disease.