CD9 and cancer: Figures 2D, E display the expression of candidate genes. Subsequent functional and pathway enrichment analyses uncovered that these genes pertained to the modulation of the Notch signaling pathway, integrin binding, ion channel regulator activity, hematopoietic cell lineage, lysosomes, and proteoglycans in cancer (Figures 2F, G). Moreover, the PPI network revealed higher connectivity for CD9, TSPAN2, TSPAN13, TSPAN15, and CD63 (Figure 2H).