NFAT IHC staining in CTCL samples. (A and B) NFAT IHC detection in 2 different samples from the same patient (38-2 and 38-4, respectively; Table 2); the 38-4 biopsy was taken 14 months later than 38-2. NFAT expression was detected in the cytoplasm in sample 38-2, in which S345F mutation was not found. However, NFAT was expressed in the cell nuclei in the biopsy 38-4 (B) with the S345F mutation. Arrows indicate negative (A) and positive (B) NFAT nuclear immunostaining. (C) NFAT expression in case 50 (Table 2) with wild-type PLCG1. The arrow indicates the cytoplasmic localization of NFAT. (D) NFAT expression in the PLCG1-S345F mutated case 14 (Table 2). In this case, a clear NFAT nuclear staining is detected (objective, 100×, immersion).