  After a very brief recollection of how my scientific collaboration with Ugo
started, in this talk I will present some recent results obtained with
localization: the deformed gauge theory partition function $Z(\vec\tau|q)$ and
the expectation value of circular Wilson loops $W$ on a squashed four-sphere
will be computed. The partition function is deformed by turning on $\tau_J
\,{\rm tr} \, \Phi^J$ interactions with $\Phi$ the ${\cal N}=2$ superfield.
  For the ${\cal N}=4$ theory SUSY gauge theory exact formulae for $Z$ and $W$
in terms of an underlying $U(N)$ interacting matrix model can be derived thus
replacing the free Gaussian model describing the undeformed ${\cal N}=4$
theory. These results will be then compared with those obtained with the dual
CFT according to the AGT correspondence. The interactions introduced previously
are in fact related to the insertions of commuting integrals of motion in the
four-point CFT correlator and the chiral correlators are expressed as
$\tau$-derivatives of the gauge theory partition function on a finite
$\Omega$-background.
