Similarly, in both groups the HCs and HAM/TSP patients, there was a significant increase in the ratio of CD86:CDs80 in B lymphocytes with IFN-β (p = 0.011 and p = 0.019, respectively) with a similar fold increase (1.6 fold and 1.7 fold, respectively). Here, IFNB1 is linked to tropical spastic paraparesis.