R-spondins can potentiate WNT signaling without LGRs!

Andres's paper in eLife describes a new signaling mechanism for the R-spondin family of secreted growth factors. R-spondins 2 and 3 can amplify WNT signals without LGRs using heparan sulfate proteoglycans, suggesting a broader scope for their function in development and stem cells! Awesome job and can't wait to see where this leads!