  Critical two-point correlation functions in the continuous and lattice phi^4
models with scalar order parameter phi are considered. We show by different
non-perturbative methods that the critical correlation functions <phi^n(0)
phi^m(x)> are proportional to <phi(0) phi(x)> at |x| --> infinity for any
positive odd integers n and m. We investigate how our results and some other
results for well-defined models can be related to the conformal field theory
(CFT), considered by Rychkov and Tan, and reveal some problems here. We find
this CFT to be rather formal, as it is based on an ill-defined model. Moreover,
we find it very unlikely that the used there "equation of motion" really holds
from the point of view of statistical physics.
