ATOH1 and small cell lung carcinoma: In SCLC, ATOH1 exerts its function by binding E box motifs at promoter and distal regulatory elements of target genes as in the developing mouse brain50 and in MCC,53 including binding to its own downstream enhancer23 (Figure 3), although this does not definitively indicate that ATOH1 is present at active versus silent chromatin loci in SCLC.