CD2 and neoplasm: Resistance of tumor cells to doxorubicin correlated only with the expression of one T-cell marker, CD2 (r = 0.51), whereas resistance to daunorubicin correlated directly with the expression of several T-cell markers (CD2, r = 0.16; CD3, r = 0.38; CD7, r = 0.07; and CD11c, r = 0.41), and the natural killer (NK) cell marker, CD56 (r = 0.50).