Immunohistochemically, these carcinoma cells were negative for all three neuroendocrine markers, i.e., synaptophysin, chromogranin A and CD56, TTF-1, CEA, CK20, h-caldesmon, α-SMA, calponin, and CD10, but specifically positive for 34βE12 (Figure 4A), CK7 and p63 (Figure 4B). Here, CEACAM5 is linked to carcinoma.