Independent of CXCR5, the ICOS+ cells were higher in the two disease groups with or without treatment compared with HC [ISN (p < 0.001) and ISP (p = 0.007) groups of AChR-MG, ISN (p < 0.001) and ISP (p = 0.012) groups of SN-MG for ICOS+CXCR5−, ISN (p < 0.001) and ISP (p < 0.001) groups of AChR-MG, and ISN (p < 0.001) and ISP (p = 0.003) groups of SN-MG for ICOS+CXCR5+)]. Here, ICOS is linked to myasthenia gravis.