GZMB and leukemia: These opposing views could be due, at least partially, to the fact that earlier studies used (i) cells lacking endogenous expression of GRβ, relying mostly on ectopic expression of GRβ (U2OS, COS7), transformed cells (rat hepatoma cells or leukemia cell lines), or yeast system, making physiological and clinical interpretation/extrapolation very challenging; and (ii) cell-based transient assays, assessing the synthetic reporter gene activities, rather than the endogenous, more relevant GC-target genes.