CCR1 and neoplasm: In addition, another study by Vallet et al. has shown that microenvironmental C-C motif chemokine 3 (CCL3), and its receptors C-C chemokine receptor type 1 (CCR1) and C-C chemokine receptor type 5 (CCR5), are important in promoting osteolytic lesion formation, through regulation of osteoclast differentiation, and tumor progression in multiple myeloma patients [175].