A glutamatergic neuron with a soma found in cortical layer 6b. They are transcriptomically related to corticothalamic-projecting neurons but have differential projections to the thalamus or anterior cingulate. [ http://dx.doi.org/10.1101/2020.10.19.34312 http://www.ncbi.nlm.nih.gov/pubmed/30382198 ]