SOX9 and small cell lung carcinoma: Although data are lacking to support a direct interaction between POU2F3 and SOX9 in normal tuft cells, a recent SCLC (i.e., cancer) study reported the direct binding of POU2F3 (and its cofactor, POU2AF2) to the SOX9 gene locus in tuft cell-like SCLC cell lines [34].