CASP3 and metastasis: Second, although there was no significant difference between the expression of HIF-1α and caspase-3 in regard to gender, age distribution, tumor size, lymph node metastasis, and BRAFV600E mutation (all p > 0.05), HIF-1α and caspase-3 expressions were associated with capsule invasion and cell subtypes of PTC (p < 0.05).