In the present study we identified the tumor cell-derived cytokine regulated-upon-activation, normal T-cell expressed and secreted RANTES (CCL5) as a strong inducer of S100A4 release from various cell types and determined that RANTES-mediated cytoskeleton-associated shedding of microparticles is a main route of S100A4 externalization. The gene discussed is CCL5; the disease is neoplasm.