Several studies have implicated Rac and Cdc42 signaling in stem cell maintenance through activation of Wnt, Notch, and YAP signaling in breast cancer, NSCLC, and lymphomas (De et al., 2017; Hicks-Berthet and Varelas, 2017; Lai et al., 2017; Olabi et al., 2018; Katoh and Katoh, 2020). Here, CDC42 is linked to breast carcinoma.