IL4 and cancer: Finally, to test whether plasticity can be enhanced by microenvironmental factors that are released by cancer associated fibroblasts, we cultured Lgr5− cells in minimal medium supplemented with HGF, FGF, IL4, and IL13 (Chen et al., 2018, Knuchel et al., 2015, Lenos et al., 2018, Todaro et al., 2007, Todaro et al., 2014).