TNFSF4 and tropical spastic paraparesis: Similar to the findings for JPX-9 cells, OX40 was detected with an anti-OX40 mAb (clones B-7B5) after 16 hours of in vitro cultivation (Figure 2A), but OX40L was not detected in cultured PBMCs from a HAM/TSP patient (HAM/TSP1) (Figure 2B).