text_1: In a naive state, blocking Wingless-Int-1 secretion from mouse embryonic stem cells inhibits self-renewal of the mouse embryonic stem cells.
text_2: Moreover, we find that Wnt proteins in combination with the cytokine LIF are sufficient to support ESC self-renewal in the absence of any undefined factors, and support the derivation of new ESC lines, including ones from non-permissive mouse strains.