  We study the inapproximability of the induced disjoint paths problem on an
arbitrary $n$-node $m$-edge undirected graph, which is to connect the maximum
number of the $k$ source-sink pairs given in the graph via induced disjoint
paths. It is known that the problem is NP-hard to approximate within
$m^{{1\over 2}-\varepsilon}$ for a general $k$ and any $\varepsilon>0$. In this
paper, we prove that the problem is NP-hard to approximate within
$n^{1-\varepsilon}$ for a general $k$ and any $\varepsilon>0$ by giving a
simple reduction from the independent set problem.
