Beyond this connection, the let-7 family of miRNAs is also known to regulate neuronal differentiation: increased expression of let 7a, let-7b, and let-7d promote cell cycle exit by repressing proliferative and cell cycle progression genes such as TLX and CCND1, which is consistent with the reduced proliferation in our BD-NPCs and smaller SVZs in the organoids [80–83]. The gene discussed is CCND1; the disease is Behcet disease.