HNRNPK and amyotrophic lateral sclerosis: In C9orf72-associated ALS cases, the nuclear depletion of hnRNP K cells in pyramidal neurons in layer IV of the motor cortex (as well as in spinal cord motor neurons) was accompanied by reduced RRM2 levels, but enhanced nuclear translocation, which suggests that the dysregulation of RRM2 may be associated with the mislocalisation of hnRNP K. In Hela cells, the knockdown of hnRNP K can lead to a reduction in RRM2 levels, while induced DNA damage can lead to the nuclear translocation of RRM2.