Complex sentence: KLF3 and KLF8 may have redundant functions as mice lacking both KLF3 and KLF8 show defects that are more severe than in either single knockout and die in utero around day 14 of gestation.
Split into simpler sentences: KLF3 and KLF8 may have redundant functions, as mice lacking both KLF3 and KLF8 show defects that are more severe than in either single knockout. They die in utero around day 14 of gestation.