The analysis of the expression of adhesion molecules which could promote leukaemia–fibroblast interactions showed that the co‐culture of both cell types induced a significant increment in the expression levels of ITGA4 (VLA‐4) and ITGAL (LFA‐1) integrins in leukaemic cells and their ligands VCAM1 and ICAM1 in CP fibroblasts (Figure 3A–C). Here, ITGA4 is linked to leukemia.