premise: Homozygous and heterozygous * * f cells , * * f and homozygous and heterozygous * * f cells were used to test each sample ; however , in the interest of <mask> and conciseness only the results obtained with homozygous * * f and homozygous * * f cells will be presented here .
hypothesis: the proper context for <mask> here should be free from obscurity and easy to understand; the comprehensibility of clear expression