The conserved cDC1 signature encompasses genes with known contribution in the biology of this lineage, such as XCR1, FLT3, and CADM1 (59), as well as additional genes which biological function in this subset remains enigmatic, such as the germinal center B-cell-expressed transcript 2 protein (GCET2), the WDFY family member 4 (WDFY4) whose polymorphism is associated to autoimmune diseases (62), and two intracellular trafficking proteins, a formin-binding protein (FNBP1) (63) and Sorting Nexin-22 (SNX22) (64) (Table 1). The gene discussed is GCSAM; the disease is autoimmune disease.