In agreement with these findings, levels of the phosphorylated form of STAT3Tyr705, AKT, and ERK 1⁄2, as well as cyclin D1 were unchanged in both parental cells and tumor spheres in response to erlotinib, whereas treatment with WZ4002 caused a more pronounced decrease of these signaling mediators in parental cells compared to tumor spheres, except for p-AKT (Figure 1C). Here, CCND1 is linked to neoplasm.