The bounded-degree wall-or-line-wall induced-subgraph conjecture

Let $G$ be a graph, let $k$ and $\Delta$ be positive integers, and let $W_{k \times k}$ denote the $(k \times k)$-wall. A subdivision of a graph is obtained by replacing its edges by internally vertex-disjoint paths, and the line graph of a graph has one vertex for each edge, with adjacency when the corresponding edges share an endpoint. The wall-or-line-wall conjecture. For all $k, \Delta > 0$, there exists $c=c(k,\Delta)$ such that every graph with maximum degree at most $\Delta$ and treewidth more than $c$ contains a subdivision of $W_{k\times k}$ or the line graph of a subdivision of $W_{k \times k}$ as an induced subgraph. This conjecture was recently proved by a different method, so it is no longer open.