Figure 1: Alveolar progenitor cells express the β4 integrin and it contributes to their function.

A) Single cell RNAseq analysis of ITGB4 expression in differentiated luminal, alveolar progenitor, and differentiated basal mouse mammary cell populations based on reference (10). B) NMuMG cells were sorted based on β4 surface expression into two distinct populations (β4^high and β4 ^low) and these populations were analyzed by flow cytometry for alveolar progenitor cell surface markers (CD24, CD49f, and CD61). C) NMUMG cells were analyzed by flow cytometry for expression of CD24, CD49f, CD61, and β4. D) NMuMG cells were sorted into alveolar progenitor (CD24^high/CD49f^high/CD61^high) and non-alveolar progenitor (CD24^low/CD49f^low/CD61^low) populations. Expression of the β4 integrin was diminished in these populations using siRNA, and their progenitor potential was assessed using serial passage mammosphere assays (E).