ADRB2 and neoplasm: In other words, those specimens with weak β2-AR expression in the tumor-free surgical margin also exhibited weak/negative immunostaining of this protein in their respective invasive tumor front; and similarly, when the immunoexpression of β2-AR was strong in normal oral epithelial cells, at the tumor-free surgical margin, the expression levels of this protein in malignant epithelial cells at the invasive front of the tumor were also high (Figure 1).