Help with t.test

Hi I have managed to do a paired t-test with a data set

i have 5 colums of data im dealing with


GENE   SampA          SampB     SampC       SampVehicle
ctcc   859             na        145             24
gtcg   45              5         54              69

and so on but they are much larger columns

each column has been split and i can do t.test on for eg sampA by doing
t.test(sampA, SampVehicle, na.rm=TRUE, paired=TRUE, conf.level=0.95)

what can I do to be able to identify which of the genes are responsible for the most variance or are the most significant.

THANKS IN ADVANCE