An ideal $I$ is called *cellular* if every variable is either a nonzerodivisor modulo $I$ or is nilpotent modulo $I$.

An ideal $I$ is called *primary* if whenever $fg \in I$ then or $f \in I$ or $g$ is nilpotent modulo $I$.

Of course, if $I$ is primary $\Rightarrow$ $I$ is cellular. 

My question is: consider a binomial ideal $I \subset \mathbb{K}[x_1, \dots, x_n]$, generated by binomials of the form $f=\prod_{i \in I} x_i - \prod_{j \in J} x_j$, for some $I,J \subset \{1, \dots, n\}$ with $I \cap J = \emptyset$ and both no empty.

What can I say about the equivalence $I$ primary $\Rightarrow$ $I$ cellular? Under which hypothesis a primary binomial ideal is cellular?

Thanks