COL1A1 and neoplasm: Based on DEGs analysis, the identified tumor cell subpopulations were characterized as PCDH1+ (PCDH1, STRA6, SEC14L2, C5AR2, and KLF4; cluster 1), PLEKHG5+ (PLEKHG5, TNFRSF25, TNNT3, ECM2, and THBS3; cluster 2), LUM+ (LUM, C1R, GPNMB, COL1A1, and PRSS23; cluster 3), and IQGAP3+ cells (IQGAP3, TROAP, DLGAP5, AURKB, and KIF20A; cluster 4) (Figure 3A,B, Table 1 and Supplementary Figure S1).