CXCR4 and adenoma: Therefore, the better characterization of CXCR4/ACKR3/CXCL12 axis in PAs (Figure 1) could pave the way for novel pharmacological approaches, especially for those adenoma subtypes (i.e., TSH and ACTH-secreting tumors, as well as NFPA) still waiting for efficacious therapeutic drugs.