MuSK-CAART cytotoxicity against mixed Nalm-6 target cells (13-3B5/3-28/24C10/192-8 (anti-Ig1/Ig2/Ig3/Fz)) was partly inhibited by polyclonal IgG from patients with MuSK MG, although specific cytotoxicity generally increased with higher effector to target ratios and longer coincubation (Fig. 2a). Here, MUSK is linked to myasthenia gravis.