BRAF and melanoma: Further, mirroring the observation in human patients, we administered vemurafenib (BRAF inhibitor) drug pellets to adult zebrafish with melanomas81 and found that clusters of Aldh1a3 cell populations increased in drug-resistant and progressing disease upon immunohistochemistry (IHC) assessment through disease stages (melanoma responding, stable, and progressive disease) (Figures 7E and 7F).