Police are appealing for witnesses after a 38-year-old man was stabbed near New Road and Pavilion Gardens, Brighton.
A Sussex Police spokesman said officers want to speak to Arron Owston, from Hove, who they believe may have vital information about the stabbing.
The victim was taken to the Royal Sussex County Hospital, Brighton, by ambulance after suffering a potentially life-threatening injury.
Following surgery, he is in an induced coma in a serious but stable condition.
Detective Inspector Ian Still said: “This would appear to have been an isolated incident but extra officers have been patrolling in the area to provide reassurance.
“We are keen to speak to anyone who saw what happened or who may have further information concerning this incident.
“We are also trying to trace Mr Owston, so would also appreciate his coming forward or hearing from anyone who has seen him recently or who may know where he is.”
Call Sussex Police online or call 101, quoting Operation Hillford or Crimestoppers anonymouslyon 0800 555 111.