Supporting this notion, we found that repeated administration of tamoxifen (twice a month), which could further improve the recombination activity of NG2‐CreER, fully blocked glioma incidence in the IGF1R (flox/flox) mice (Figure 2J).We noted that the survival of these mice with repeated tamoxifen administration was only minimally further extended (Figure 2I). This evidence concerns the gene IGF1R and central nervous system cancer.