Hefetz–Mütze–Schwartz conjecture on antimagic orientations

Let $G$ be a connected undirected graph. An antimagic orientation consists of an orientation $D$ of $G$ and a bijection from $E(G)$ to $\{1,2,\ldots,|E(G)|\}$ such that the vertex sums, defined as the sum of labels on incoming edges minus the sum of labels on outgoing edges, are distinct for all vertices. Hefetz–Mütze–Schwartz conjecture. Every connected graph admits an antimagic orientation. The source states that this remains an unsolved question, although many graph families are known to satisfy it.