By RNA in situ hybridization (RISH), we verified enriched expression of IGF1 and CXCL13 in the inner stroma adjacent to BPH hubs, including among hubs that were microdissected and transcriptionally profiled (exemplified by Hub-1 in Figure 3, A–D, and quantified in Supplemental Table 4), as well as in additional independent hubs (exemplified by Hub-7 in Figure 3, E–K). This evidence concerns the gene CXCL13 and benign prostatic hyperplasia.