CEACAM5 and neoplasm: Gu et al. [18] revealed that SUVmax of PET/CT, gender, tumor histology, and CEA were significant indicators for EGFR mutation, and performed a formulation as follows: Y = ex/(1 + ex), X = −8.273 + 1.713 × gender + 1.402 × histology + 0.735 × CEA +0.921 × SUVmax, with the cutoff point 0.3432.