Abstract: Development of the telencephalon relies upon several signaling centers – localized cellular populations that supply secreted factors to pattern the cortical neuroepithelium. One such signaling center is the cortical hem, which arises during embryonic development at the telencephalic dorsal midline, adjacent to the choroid plexus and hippocampal primordium (Figure 1A). While the cortical hem has also been described in reptiles and birds, most of our knowledge about the developmental roles of the cortical hem is derived from the analysis in mice. The cortical hem produces several types of secreted molecules, including wingless-related integration site (Wnt) and bone morphogenetic (Bmp) proteins. The cortical hem is particularly important for the development of the hippocampus, which is involved in learning and memory, and the neocortex, which is the most complex brain region that mediates multiple types of behavior and higher cognitive functions (Mangale et al., 2008; Dal-Valle-Anton and Borrell, 2022). The essential role of the cortical hem in brain development has brought significant interest to this signaling center. In this perspective, we summarize the contribution of our and other laboratories in identifying the cortical hem-related developmental mechanisms and outline unresolved questions and future directions in the field, including analysis of a possible role of cortical hem in brain evolution and developmental brain disorders.