SR-1 promotes the development of CD56^dim NK cells. (A) Real-time PCR showing CD56 expression from NK cells expanded with DMSO (control) or SR-1 on day 7 (D7) and day 14 (D14). The value on the y axis shows fold change in gene expression relative to D7 control NK cells. (B) Representative fluorescence-activated cell sorter histograms showing CD56 expression in day 7 or 14 expanded NK cells with SR-1 (1 μm) or DMSO (control). (C) Quantification of CD56 expression by measuring mean fluorescence intensity in NK cells expanded with SR-1 or control from multiple donors on days 7 or 14. Values show mean ± standard deviation (SD; n = 6, P < .001). ns, not significant. (D) RNA-seq data showing the expression of KIT in NK cells expanded with DMSO (control) or SR-1. Value show mean ± SD (n = 3, P < .001). (E) Fluorescence-activated cell sorter analysis showing KIT expression in NK cells expanded with SR-1 or control (DMSO) on day 14. Mean fluorescence intensity was used to determine protein expression. The values show mean ± SD (n = 3, P < .01).