CD4 and breast carcinoma: The role of Sos1 as a regulator of cell migration has been described in macrophages (Baruzzi et al., 2015), glioblastoma cells (Kapoor and O’Rourke, 2010) breast cancer cells (Lin et al., 2018), peripheral CD4(+) T cells (Guittard et al., 2015), etc.