ACTA1 and neoplasm: The histological semi-quantitative analysis revealed a significant (p ≤ 0.05) increase of tumor vascularization after high dose hyperthermia (Fig. 4E).Interestingly, the expression of smooth muscle actin (α-SMA), as indicator for the presence of mature endothelial cells, decreased after (high and low dose) hyperthermia (Fig. 4F).