Another candidate transcriptional regulator of Foxn1 in TECs is the T box transcription factor TBX1, mutation of which is thought to cause DiGeorge Syndrome 98, 99: induced expression of TBX1 in Foxn1 expressing cells of the E11.5 3PP resulted in down‐regulation of Foxn1 expression, indicating that TBX1 can repress Foxn1 transcription in TECs 100. Here, TBX1 is linked to 22q11.2 deletion syndrome.