Like HH activation, activation of STAT-3 has been shown to increase proliferation of BCSCs.20 IL-6-STAT3 signaling is reported to indirectly upregulate canonical hedgehog signaling in other tumor models.21 Whether the increase of SHH observed in our model after chemotherapy is directly or indirectly regulated by IL-6-STAT3 signaling is unknown. This evidence concerns the gene IL6 and neoplasm.