To investigate the effect of PEGylated α-MMC and PEGylated MAP30 on cell viability and proliferation, JAR cells were seeded on 96-well plates and were treated with increasing concentrations of PEGylated RIPs and un-PEGylated counterparts for 72 hours ( Figure 7A ) and for different times at 1.5 mg/mL ( Figure 7B ). Statistical analysis revealed that the concentrations of 1.5, 0.3, and 0.06 mg/mL started to significantly reduce the proliferation of cells after 48 and 72 hours of incubation. The analyses with the result of Figure 7A not prominent after 24 hours of treatment, but continued incubation for 48 or 72 hours with the proteins enhanced the cytotoxicity on cells.