DNAJB5 (DnaJ heat shock protein family member B5) is a molecular chaperone protein that functions in protein folding and the cellular response to proteotoxic stress. As a member of the Hsp40 family, DNAJB5 facilitates protein folding and prevents aggregation of misfolded proteins 1. In the context of neurodegenerative disease, DNAJB5 plays a protective role against TDP-43 pathology associated with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). DNAJB5 is upregulated early in disease progression and co-localizes with TDP-43 pathology in diseased human motor cortex; overexpression decreases TDP-43 aggregation in cell and neuron cultures, while DNAJB5 knockout exacerbates motor impairments in mouse models 1. DNAJB5 expression is regulated by microRNA-21 (miR-21), which targets DNAJB5 to mediate drug resistance in cholangiocarcinoma; restoration of DNAJB5 levels re-sensitizes resistant cells to HSP90 inhibitors 2. Additionally, DNAJB5 expression is altered in several disease contexts including inflammatory bowel disease (downregulated in ulcerative colitis) 3, epilepsy (upregulated as part of a neuroprotective response) 4, and serves as a biomarker for particulate matter air pollution exposure 5. These findings suggest DNAJB5 as a potential therapeutic target in neurodegenerative and malignant diseases.