In contrast, emodin and rhein when used with cisplatin or cyclophosphamide only increased in caspase 9 activity in lymphoid leukaemia cells (P ≤ 0.05) (Figure 4); whereas cis-stilbene combined with cisplatin increased in caspase 8 and 9 activity, but only in lymphoid leukaemia cell lines (P ≤ 0.05) (Figure 4). Here, CASP9 is linked to lymphoid leukemia.