IL6 and congenital rubella syndrome: In several studies, tocilizumab has proven to be effective for severe or life-threatening CRS, and usually patients with CRS rapidly respond to tocilizumab—fever and hypotension often resolve within a few hours [51, 52]; however, considerations have been given to use tocilizumab pre-emptively or even as prophylaxis, as blocking IL‐6 with tocilizumab neither significantly compromised therapeutic efficacy of CAR‐T cells, nor did it negatively affect prognosis of the CAR‐T cell recipients [3, 9, 48, 53].