  A permutation $\pi$ contains a permutation $\sigma$ as a pattern if it
contains a subsequence of length $|\sigma|$ whose elements are in the same
relative order as in the permutation $\sigma$. This notion plays a major role
in enumerative combinatorics. We prove that the problem does not have a
polynomial kernel (under the widely believed complexity assumption $\mbox{NP}
\not\subseteq \mbox{co-NP}/\mbox{poly}$) by introducing a new polynomial
reduction from the clique problem to permutation pattern matching.
