IL2 and lymphoma: Using Fisher’s exact tests, the low-frequency group had significantly more aggressive diagnoses (i.e., acute, lymphoma, and unfavorable chronic subtypes) based on the Shimoyama classification at the time of blood sampling (10 out of the 16 patients in this group, p = 0.0324), demonstrating that ATL patients with an aggressive-type diagnosis according to the Shimoyama classification tended to exhibit poor expansion of γδ T cells with PTA/IL-2/IL-18.