The present invention relates to methods for generating mature insulin-producing β-like cells comprising the steps: (a) isolating, purifying and/or enriching β-cell progenitor cells from a population of cells； (b) differentiation of the β-cell progenitor cells into immature insulin-producing β-like cells； and (c) maturation of the immature insulin-producing β-like cells into mature insulin-producing β-like cells, comprising exposing the immature insulin-producing β-like cells to calcitriol or an analogue thereof. More particularly, the present invention relates to methods for generating mature insulin-producing β-like cells for use in treating diabetes.
