JAM-C is involved in leukemic cell nesting under stromal cells but does not directly control AP-1 activation. (A) Graph showing the repartition of SKM-1^JAM-C+ and SKM-1^JAM-C− cells upon 7 hours of coculture with HS-5 stromal cells. (B) Graph showing the repartition of SKM-1^JAM-C+ and SKM-1^JAM-C− cells upon 7 hours of coculture with HS-27 stromal cells. (C) Graph showing the percentage of GFP-expressing SKM-1^JAM-C+ (red) and SKM-1^JAM-C− cells (blue) in absence of treatment and upon phorbol myristate actetate (PMA) activation. Variant cell lines were transduced with lentiviral constructs containing AP-1 GFP reporter (plain bars) or control (Ctrl) GFP reporter lacking AP-1 binding sites (dashed bars), as indicated. (D) Graph showing the percentage of GFP-expressing SKM-1^JAM-C+ (violet) and SKM-1^JAM-C− cells (orange) in absence of coculture or after 7 hours of coculture with HS-5 stromal cells. (E) Graph showing the percentage of GFP-expressing SKM-1^JAM-C+ (violet) and SKM-1^JAM-C− cells (orange) in absence of coculture or after 7 hours of coculture with HS-27 stromal cells. Data represent mean ± SEM from n = 3 independent experiments: ns, not significant; ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001.