DIO2 and squamous cell carcinoma: Based on the above consideration, we searched for up-stream regulators of D2 expression in the context of Squamous Cell Carcinoma (SCC) and found that the tumor suppressor Trp53 (mus musculus)/TP53 (human), one of the most commonly mutated genes in over 50% of all human diagnosed cancers14, acts as transcriptional inhibitor of D2.