In addition, we attempted to determine whether the formation of tumor spheroids was mediated by the activated STAT3 signaling pathway in the cells cultured on polymer X. In line with SKOV3 ovarian cancer cells, STAT3 signaling was also activated in tumor spheroids formed by the various GBM cells and HeLa cells cultured on polymer X (Figure 5B–D). This evidence concerns the gene STAT3 and glioblastoma.