MKI67 and diffuse large B-cell lymphoma: In DE-DLBCL patients with Ki67 index ≤75%, there was no significant difference in CRR between the ZR-CHOP group and the R-CHOP group after 4 courses (75% vs. 50%; P= 0.432) or 6 courses of treatment (100% vs. 66.7%; P= 0.276).