While extra centrosomes can be causative of chromosomal instability (CIN) by promoting merotelic kinetochore–microtubule attachments in mitosis (Ganem et al. 2009; Silkworth et al. 2009), they may promote oncogenesis in additional ways unrelated to CIN; e.g., by increasing Rac1 activity that facilitates invasive cellular behavior (Godinho et al. 2014). Here, RAC1 is linked to cervical squamous intraepithelial neoplasia.