As expected, co‐culturing PBMCs with MM cell lines both M‐MDSCs and Treg subpopulations resulted significantly increased after 48 h (Figure 5I,L), but only Treg expansion was reduced by AZD3965 (of about 9 ± 2.7% and 20.6 ± 2.9% for PBMCs co‐cultured respectively with U266 and NCI‐H929 compared to co‐culture without MCT1 inhibitor; p < 0.01 and p < 0.0001; Figure 5L). The gene discussed is MCAT; the disease is Miyoshi myopathy.