To evaluate the effect of defactinib in the presence of leukaemia‐stroma interactions, we exploited the traditional 2D culture, thus seeding CLL cells in the presence of HS5 cells (4 cases), treating with 4 μM defactinib and collecting them after 48 h for flow cytometry analysis, where we used the Annexin V‐PI Kit to evaluate cell death and we could not detect any significant protective effect at this concentration and time point (Figure S1A). Here, ANXA5 is linked to leukemia.