Former Carolina Panthers tight end Greg Olsen said his son, TJ, has now hit a major milestone in his heart health journey, NBC affiliate WCNC reports.In a video shared on Twitter on Wednesday, Olsen showed a video of TJ ringing a bell at Levine Children's hospital in Charlotte. It marks an important day TJ has looked forward to since his admission to the intensive care unit.TJ was born with congenital heart disease. He lived the first eight years of his life with a modified heart. In May 2021, Greg Olsen shared TJ's heart was nearing its end, and a heart transplant would be necessary. A donor match was found in mere days, and TJ soon underwent surgery. The surgery was successful, and TJ thanked his father's followers for their prayers and support on his long road to recovery.Greg Olsen continued to share gratitude for prayers and support from fans, family, friends and community members. He had previously taken time to specifically request prayers for the donor family, who so far the Olsens do not know, according to WCNC.