What is the function of R-spondin 1 and noggin in non-damaged gallbladders?
['R-spondin 1 and noggin facilitate expansion of resident stem cells from non-damaged gallbladders.', 'R-spondin 1 and noggin facilitate expansion of resident stem cells from non-damaged gallbladders.']
['R-spondin 1 and noggin facilitate expansion of resident stem cells from non-damaged gallbladders.']
['The expansion of resident stem cells.']