FCER2 and posterior cortical atrophy: Moreover, detailed CyCIF characterization using an expanded TLS-focused panel (Supplementary Table 1) of an HGG PCa having ICs with ICAT value in the lower quartile (< 13.7 = Q1, corresponding to mature and immature histological classes; Fig. 3h) showed that organized BICs contained foci of CD21+ and CD23+ follicular dendritic cells (FDCs).