CEACAM5 and neoplasm: Interestingly, patient cohorts with different CEA expression levels showed different sensitivity to λ. For patients with intermediate CEA expression (1E+4–3E+5 sites/cell), λ has significant impact on tumor diameter, since λ ensured the formation of stable biTTC for cells with lower CEA expression; for high CEA expression cells (3E+5–1E+6 sites/cell), the sensitivity was reduced since the effect of λ on high expression tumor cells was moderate (Fig. S4A,B).