The father of Kierra Coles, a postal worker who disappeared last October, urged for anyone with information on missing person cases in the area to come forward.
Coles was last seen on surveillance video leaving her home near 81st and Vernon in the Chatham neighborhood. She was pregnant at the time and due in April.
Police previously said they suspected foul play in Coles' disappearance.
Joseph Coles said police don't have any other leads in the search for his daughter, but he refuses to give up.
"I do believe my daughter is still alive," Joseph Coles said at Daley Plaza on Monday.
There's a $46,000 reward for information leading to her whereabouts. Anyone with information about Coles is asked to call the Area South Special Victims Unit at (312) 747-8274 or the U.S. Postal Inspection Service at (877) 876-2455.
LaShann Walker will not give up either. Her intellectually disabled daughter Diamond Bynum went missing from her home in Gary, Indiana, along with her 2-year-old nephew King Walker, nearly four years ago.
At the time, it was believed Bynum had wandered off and gotten lost.
"My world has just been turned upside down," said LaShann Walker . "Sometimes I feel like I'm in this by myself."
The sister-in-law of Stacy Peterson, a Bolingbrook mother who disappeared nearly 12 years ago, also spoke out on Monday.
Peterson was 23 when she went missing in 2007. Her husband, former Bolingbrook Police Sgt. Drew Peterson, was a suspect, but he was never charged. He's serving time for killing his previous wife, Kathleen Savio, and a murder-for-hire plot to kill Will County State's Attorney James Glasgow.
Stacy Peterson's family still wants to find her remains.
Her sister-in-law, Norma Peterson, has since become a domestic abuse advocate. She's helping to promote what is known as an Evidentiary Abuse Affidavit, created in the wake of Peterson's disappearance.
"What it does is that it allows victims to be able to document their abuse, so that they can let people know what was going on with them at the time," Norma Peterson said.