Overall survival in RCHOP and CHOP datasets. Overall survival in RCHOP dataset. (Ai-iii) and in CHOP dataset (Bi-iii) for 4 quartile groups using clinical factors only (Ai,Bi), and clinical factors + molecular predictors (Aii-iii, Bii-iii). Survival risk scores derived from the given multivariable Cox model were used to rank cases that were then divided into quartile groups.