ACTA1 and neoplasm: Additionally, EPC proportion was positively correlated with tumour perivascular cell number (α‐SMA or NG2 density) in tumours (α‐SMA density in HT‐29 tumours, r = 0.5159, P = 0.0002; NG2 density in Colon26 tumours, r = 0.7242, P < 0.0001; Figure 3e).