The unexpected high uptake of 18 F-FLT in FL relative to its cell proliferation reflected by the higher 18 F-FLT- SUVmax to MIB-1 ratio in FL compared to DLBCL is in line with a previous study, where the ratio of 3H-thymidine uptake to percentage of MIB-1-positive cells in FL was 1.5 times that in DLBCL, associated with relatively increased expression of DNA repair proteins (PCNA)[11]. Here, PCNA is linked to diffuse large B-cell lymphoma.