BECN1 and thyroid cancer: To investigate potential function of Beclin 1 in thyroid cancer cells, FRO cells were transfected with empty vector or specific shRNAs against Beclin 1 (shBeclin 1), three of them (shBeclin 1#2, shBeclin 1#3 and shBeclin 1#4) significantly suppressed Beclin 1 expression in FRO cells (Figure 1A).