Table 2. IHC analysis of Ep-ICD and EpEx subcellular localization in thyroid tissues.

Thyroid Tissue	Number of cases (n)	Nuclear Ep-ICD Positive (n)	Nuclear Ep-ICD (%)	Loss of Membrane EpEx (n)	Loss of MembraneEpEx (%)	ESLI positive (n)	ESLI positivity (n)
Benign nodule	16	2	12.5	0	0	0	0
Non-aggressive PTC	63	10	15.9	7	11.1	38	60.3
Aggressive PTC	121	85	70.3	111	91.7	118	97.5

The IHC score cut-off values for positivity were defined as ≥2 for nuclear Ep-ICD positivity; ≥5 for cytoplasmic Ep-ICD positivity and ≤5 for loss of membranous EpEx expression. ESLI cut-off ≥6 was used to determine ESLI positivity for distinguishing PTC from benign cases; and a cut-off value of >10 was used to determine ESLI positivity for distinguishing aggressive PTCs from non-aggressive PTCs.