The molecular mechanism of the synergistic anticancer activity of MMB + CFM-4.16 combinations. Western blotting of the oncogenic P-STAT3, tumor suppressor CARP-1, T-STAT3, T-JAK2, and GAPDH for the individual drugs and MMB + CFM-4.16 combinations in both MDA-MB-231 and MDA-MB-468 at 12 and 48 h. MMB + CFM-4.16 combinations showed simultaneous downregulation of P-STAT3 and up-regulation of the CARP-1 compared to the control and individual drugs at both 12 and 48 h in both cell lines. The combinations, especially the T combo, were able to upregulate CARP-1 in the first 12 h compared to individual CFM-4.16 in both cell lines. The potency of NT combo and T combo was owing to their sustained release and prolonged effect on suppressing P-STAT3 both cell lines. Even the free combo was able to completely wipe out P-STAT3 in the first 12 h in MDA-MB-231, yet, the impact was short-term effect as there was little upregulation of P-STAT3 at 48 h unlike the NT and T combo which had stable and ascending cumulative effect. There was no change in the T-SAT3 and T-JAK2 in both cell lines. GAPDH was used as an internal control of protein loading. Note: T combo (CD44-T-PNPs + MMB), NT combo (NT-PNPs + MMB) and free combo (CFM-4.16 + MMB) where MMB means momelotinib. The densitometry and uncropped blots are shown in Figure S5.