We have previously reported that LoVo cells show high CEA expression, LS174T cells show moderate to high CEA expression, HCT116 cells show low CEA expression, and HEK293 cells show no expression of CEA.26 Anti-CEA or Myo-Affimer tagged nanoparticles (1 mg mL−1) were incubated with colorectal cancer and control cell lines for 24 h and then imaged using confocal microscopy, and cell-specific fluorescence was quantified. This evidence concerns the gene CEACAM5 and colorectal cancer.