CD28 and breast cancer: Another study targets AXL, a receptor tyrosine kinase (RTK) that overexpresses in various tumours, particularly breast cancer, with AXL‐CAR‐T cells containing 3rd generation (CD28.41BB.CD3‐) of AXL‐specific CAR led to significant cytolytic activity and cytokine secretion against AXL positive cells MDA‐MB‐231 in vitro.