CTSS and Alzheimer disease: The editing level at the GluA2 Q/R site in the hippocampal region is lower in AD, which induces altered Ca2+ influx and neuron death.178 In human endothelial cells under pro-inflammatory conditions, cathepsin S (CTSS) mRNAs, encoding a cysteine protease, can be targeted by ADAR1, thereby recruiting HuR to improve its stability and translation.