A $42,508 pilot grant is available to perform critical investigations into the etiology and pathogenesis of HHV-8-negative/"idiopathic" multicentric Castleman disease (iMCD). We seek to fund research that will improve understanding of the etiology, genomic aberrations, aberrant cell populations, dysregulated signaling pathways, and/or effector cytokines in iMCD. Applications that include strong preliminary data from discovery-level studies that need funding for targeted function characterizations of suspected pathological genomic aberration(s) are preferred. Functional validation studies should provide information on the genomic aberration identified, functional studies to demonstrate the effect of the aberration and hypothesized mechanisms for how the aberration leads to iMCD pathogenesis. If preliminary data suggests that the aberration is acquired, proposals should also include studies to identify the harboring cell population. The Castleman Disease Collaborative Network (CDCN) will support the project through sample procurement, as needed, and can provide its expertise and guidance to facilitate the success of the project. This grant is made possible by the Castleman Disease Collaborative Network and Team CDCN.