KRAS and glioblastoma: Since our previous finding from a screen of glioblastoma [20] and the data in Fig. 1 of this study suggested an important role of ARL2 in the progenitor/stem‐like population of normal colon tissues and colon cancer tissues, we next directly examined the impact of silencing ARL2 expression in BCC and CSC using the colon cancer cell lines HCT15 and HT29, which harbor mutant and wild‐type K‐RAS, respectively.