meyer paper "Noise in Current-commutating CMOS Mixers&q

hi, I read "Noise in Current-commutating CMOS Mixers",in this paper, he said "
it is worth noticing that no specific value of VT is needed to calculate the drain current of M1 and M2. The behavior ofthe switching pair is independent of VT and therefore to a first order is independent of the body effect and the common-mode
LO voltage. This observation allows us to omit the small-signal
body transconductance below.

M1 M2 are switching pair. VT is thresholed voltage.

I think the VT affects the behavior. I do not understand what he means.

As ur paragraph the threshold voltage will not be considered in the calculation of the drain current and it has no effect on the behavior