CXCR4 and lymphoma: At present, prospective trials for CXCR4-directed RLT are in preparation, aimed at investigating the activity, tolerable dose and side effects of [90Y]Y-PentixaTher in patients with recurrent or refractory primary or isolated secondary central nervous system lymphoma, (PTT101, EudraCT No. 2021–002364–43), multiple myeloma (MM) and other lymphoma subtpes (COLPRIT trial, EudraCT No. 2022–002989–33)24, 25.