The other nominated gene---IGF-BP4---

By using the very strict criteria to nominate genes that promote cardiomyogenesis, we found only two genes as candidates. Grem1 and IGF-BP4 were nominated as candidates of the cardiomyogenic factors. Grem1 indeed accelerated cardiomyogenesis of murine teratocarcinoma cells as published in this manuscript. It has just recently published in Nature (Zhu W, et al., IGFBP-4 is an inhibitor of canonical Wnt signaling required for cardiogenesis) that IGF-BP4 is involved in cardiogenesis. We did not include this information in our Grem1 paper (address shown below), Results section, the paragraph “GeneChip and statistical analysis”.

Our Grem1 paper is available at:
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002407

The abstract of Prof. Komuro's Nature paper is available at:
http://www.ncbi.nlm.nih.gov/pubmed/18528331?ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum