RAG1 and Huntington disease: While our data were consistent with regard to the aberrant relationships of astrocytes with their partnered synapses in HD mice, and of the prominence of this effect throughout postsynaptic spine maturation, our use of T- and B-cell-deficient Rag1−/− hosts—done so as to permit later comparisons of synaptic structure in human glial-transplanted HD hosts—poses a potential caveat to this study.