In breast cancer, CTCs from CTCs associated with neutrophil or macrophage clusters with a predominance of neutrophils mediated by vascular cell adhesion molecule-1 (VCAM1), CTCs in clusters exhibited upregulation of positive regulators of the cell cycle and DNA replication program and increased mutation frequency compared to individual CTCs, suggesting that direct interaction of CTCs with neutrophils increased the likelihood of metastatic colonization CTCs [163]. The gene discussed is VCAM1; the disease is breast cancer.