SMAD6 and neoplasm: This revealed a number of known BMP4 target genes (ID1, ID3 and SMAD6) and others that were identified in a recent publication [13], including urothelial cancer-associated 1, UCA1, and atonal BHLH transcription factor 8, ATOH8, as being amongst the most significantly upregulated genes by BMP4 (Figure 1a), confirming in 231-HM tumours the known transcriptomic regulation by BMP4.