To support the proposal that cancer cells of carcinomas interact with the chemokine/chemokine receptor system to escape immune attack, we defined how they assemble a TGM2-dependent, filamentous coating of CXCL12–KRT19 heterodimers that restricts T cell motility and suppresses the intratumoral accumulation of T cells. The gene discussed is CXCL12; the disease is cancer.