PDCD1 and neoplasm: Notably, malignant cells from the PD-1+SMI group were mainly found in the apoptotic branch (NNMT+ and FSTL1+ tumor cells), whereas those from the PD-1 and IgG groups were clustered in the invasive and migrative branches (H3F3B+ and FOSB+ tumor cells), and finally, malignant cells from the SMI group were mainly clustered in the CSCs and EMT branches (NEAT1+ and S100A4+ tumor cells).