In cluster 4, which mostly existed in the gem group, cells expressed high levels of CCR2, CCL2, and S100A4 genes that are associated with tumor progression and metastasis (Dahlmann et al., 2016; Li et al., 2017) (Figures 3E, F, Supplementary Figures S1D, F). The gene discussed is S100A4; the disease is neoplasm.