Compared to UT cells, all three CAR T cell types elicited cytotoxicity against MM cells: the tandem CAR T cells displayed the most robust killing (P < 0.05 against the single-nanobody constructs under all tested conditions; P < 0.01 at the 1:1 ratio for RPMI 8226 cells and at the 4:1 ratio for MM.1S cells and against the Nb2 construct for RPMI 8226 cells), followed closely by Nb1 CAR T cells (at the 4:1 ratio, P < 0.05 for MM.1S and P < 0.01 for RPMI 8226) (Fig. 6a and Supplementary Fig. 6a). Here, CD177 is linked to Miyoshi myopathy.