MSC growth in presence of three different lots of PL and PI-PL. MSC 1,2,3,4,5 were assessed in their growth ability by measuring doubling time (DT) for each culture experiment, in the presence of PL1,2,3 and PI-PL1,2,3 series. Data are presented as the average ± standard deviation of DT obtained in the presence of each PL or PI-PL for different MSC populations. Statistical comparison was made by ANOVA which states the absence of any significant difference among culture series. *Statistical significance was evaluted between the indicated groups by post-hoc Scheffe’s F test.