Dr. Carl June, the principal investigator of this trial, made the following remarkable statement to the New York Times on Feb 02, 2022, which reflects the authors dilemma regarding the CLL prolonged presence: “We cannot find any leukemia cells, perhaps they are still in tiny quantities and emerging only to be knocked back by cytotoxic CD4+ CAR T-cells, like whack-a-mole, or they might have been finally eradicated back in 2010” [14]. The gene discussed is CD4; the disease is leukemia.