CD38 and neoplasm: The levels of NGAL-R/CD38 were significantly higher in the majority of tumor cell samples from the relapsed group (CD38: mean 40.57% ± 8.85; NGAL-R: mean 41.0% ± 9.63) than in the remission group (CD38: mean 14.88% ± 2.45; NGAL-R: mean 13% ± 4.21) (2.7 and 3.1 times more, respectively; p = 0.005 and p = 0.019, respectively) (Figure 2c).