 Migration of NCCs is primarily induced by BMP signaling and its inhibitor, Noggin.In some invertebrates, e.g., Porifera, Cnidaria, Ctenophora and some triploblasts (the acoelomates), the term "mesenchyme" refers to a more-or-less solid but looselly organized tissue consisting of a gel matrix (the mesoglea) with various cellular and fibrous inclusions, located between epidermis and gastrodermis.In some cases, the mesoglea is noncellular.