Compound K, a gut microbiota-derived metabolite, has demonstrated anti-migration properties in glioblastoma via the stromal cell-derived growth factor 1 (SDF-1), by reducing PKC and ERK phosphorylation, potentially serving as a predictive, prognostic, and diagnostic biomarker for therapy response [89,90]. The gene discussed is CXCL12; the disease is glioblastoma.