  A pair of the 2D non-unitary minimal models $M(2,5)$ is known to be
equivalent to a variant of the $M(3,10)$ minimal model. We discuss the RG flow
from this model to another non-unitary minimal model, $M(3,8)$. This provides
new evidence for its previously proposed Ginzburg-Landau description, which is
a $\mathbb{Z}_2$ symmetric theory of two scalar fields with cubic interactions.
We also point out that $M(3,8)$ is equivalent to the $(2,8)$ superconformal
minimal model with the diagonal modular invariant. Using the 5-loop results for
theories of scalar fields with cubic interactions, we exhibit the $6-\epsilon$
expansions of the dimensions of various operators. Their extrapolations are in
quite good agreement with the exact results in 2D. We also use them to
approximate the scaling dimensions in $d=3,4,5$ for the theories in the
$M(3,8)$ universality class.
