Laboratory tests revealed leukocytosis (white blood cell count, 10 960/μL), elevated lactate dehydrogenase (401 U/L), and markedly increased tumor markers, including carcinoembryonic antigen (CEA) (525.1 ng/mL) and cytokeratin 19 fragment (CYFRA 21‐1) (46.5 ng/mL) (Table 2). Here, CEACAM5 is linked to neoplasm.