After using CRISPR/Cas9 to knock out the genes that modulate CD5 and CD7 expression, the researchers compared the expression status and tumor-killing efficiency of tandem CARs and dual CARs (cell lines: Jurkat, CCRF-CEM, MOLT-4, SUP-T1, Raji; animal model: 6-week-old female NSG mice). Here, CD7 is linked to neoplasm.