Vav family of GEFs are required for the development of breast cancer, leukemia and skin cancer (Chang et al., 2012; Citterio et al., 2012; Menacho-Márquez et al., 2013), while Tiam1 overexpression correlates with tumor progression in pancreatic cancer, breast cancer and colorectal cancer (Li et al., 2016; Ding et al., 2018; Izumi et al., 2019). The gene discussed is TIAM1; the disease is leukemia.