STAT5A and cancer: Work on the inhibition of STAT5 indicates its potential in chemoprevention; reports investigating the progression of early lesions to full‐blown cancers have demonstrated a dependency on STAT5 activation in order to evade apoptosis and pharmacological inhibition of JAK (AG490, ruxolitinib) or STAT5 (C188‐9) led to regression of early lesions (Haricharan et al, 2013; Johnston et al, 2018).