YAP1 and small cell lung carcinoma: Furthermore, activator protein-1 (AP-1) sites were one of the top hypermethylated motifs in T-SCLC tumors [55], which is of particular note, since AP-1 proteins are critical partners of YAP/TAZ [96,97], which, as discussed above, are silenced during SCLC transformation [48,49,55].