The function of CCR1 (C-C motif chemokine receptor 1, Ensembl gene identifier ENSG00000163823) is as follows. Chemokine receptor that plays a crucial role in regulating immune cell migration, inflammation, and immune responses (PubMed:14991608). Contributes to the inflammatory response by recruiting immune cells, such as monocytes, macrophages, T-cells, and dendritic cells, to sites of inflammation for the clearance of pathogens and the resolution of tissue damage. When activated by its ligands including CCL3, CCL5-9, CCL13-16 and CCL23, triggers a signaling cascade within immune cells, leading to their migration towards the source of the chemokine (PubMed:15905581, PubMed:38417634). For example, mediates neutrophil migration after activation by CCL3 leading to the sequential release of TNF and leukotriene B4 (By similarity). Also mediates monocyte migration upon CXCL4 binding (PubMed:29930254). Activation by CCL5 results in neuroinflammation through the ERK1/2 signaling pathway (By similarity). {ECO:0000250|UniProtKB:P51675, ECO:0000269|PubMed:14991608, ECO:0000269|PubMed:15905581, ECO:0000269|PubMed:29930254, ECO:0000269|PubMed:38417634}.