PCNA and neoplasm: In line with their ability to promote tumour growth, mixing with CrT/TICs strongly enhanced EGFR signalling activation, as demonstrated by the increased phosphorylation levels of EGFR, ERK1/2, and AKT, increased the proliferation ability, as demonstrated by increased levels of Ki‐67 and PCNA (Figure 6C,D), and decreased apoptosis in xenograft tumours (Figures 6E).