Transgenerational epigenetic inheritance requires a much deeper analysis.

In his article, Szyf [1] has addressed the key challenges in and the controversies surrounding nongenetic inheritance. However, crucial findings that are important to counter two major criticisms held against transgenerational inheritance, especially in mammals--namely epigenetic memory survival across generations, and soma-to-germline transfer of heritable information--need additional discussion. Given the far-reaching implications of nongenetic inheritance on the one hand, and the skepticisms about its existence on the other, it is important that the advances concerned are examined deeply. The following discussion fills the gap left by Szyf [1] and provides an integrated perspective.