Recent studies highlight the role of labile copper in theregulation of proteins involved in cell growth and proliferation asmitogen-activated protein kinase 1 (MEK1/2) or extracellular signal-regulatedkinase 1 (ERK1/2)19,20 Therefore, copper plays a centralrole in different key processes related to cancer growth, and regulatingintracellular copper levels represents a promising and underexploredalternative approach for cancer treatment. Here, MAP2K1 is linked to cancer.