CXCL12 and neoplasm: Their natural tumor-tropism is a crucial feature of MSCs as drug delivery carriers, with tumor tissues secreting cytokines (like TNF-α, IL-6, and SDF-1) that activate MSC-related signaling pathways (such as PI3K/Akt, MAPK, JAK/STAT), inducing their migration to the tumor microenvironment [295].