The above review shows that plant extracts have an effect on stem cell proliferation or directed differentiation and play an important role in solving the problem of insufficient endogenous stem cells and directed differentiation of stem cells; In immune cell therapy, the effect of plant extracts on stem cells are reflected in the beneficial effects on CD4+ T-cells and CD8+ T-cells and the improvement of the tumour microenvironment. The gene discussed is CD8A; the disease is neoplasm.