This invention relates to stem cell microparticles and miRNA isolated from these microparticles, their use and production, in particular neural stem cell microparticles and their use in therapy. The stem cell microparticle is typically an exosome or microvesicle and may be derived from a neural stem cell line. The neural stem cell line may be a conditionally-immortalised stem cell line such as CTX0E03 (deposited at the ECACC with Accession No. 04091601). Identified miRNAs include hsa-miR-1246, hsa-miR-4492, hsa-miR-4488 and hsa-miR-4532.
