CLEC10A and amyotrophic lateral sclerosis: To elucidate the potential role of HERV-K in the pathogenesis of ALS, a transgenic mouse line expressing the HERV-K HML-2 Env protein in neurons has been generated.37 The transgenic animals develop progressive motor neuron degeneration involving both the upper and lower motor neurons, atrophy of the motor cortex, DNA damage and morphological abnormalities of the neurons resulting in a 50% mortality rate by 10 months, suggesting that HERV-K expression is a cause rather than a consequence.