Interactions with melanoma cells results in an increase in the expression of chemokine C-C motif ligand 8 (CCL8) and chemokine C-C motif ligand 15 (CCL15) by tumor-associated macrophages (TAMs) and subsequent stimulation of the C-C chemokine receptor type 1 (CCR1) present, among others, on monocytes. The gene discussed is CCL8; the disease is melanoma.