Cloning pioneer Hwang Woo-suk on Thursday remained in the hospital and did not to go his lab.

A source at Seoul National University Hospital said that over the past three days, Hwang has gone to his lab from his hospital bed.

In the morning, MizMedi Hospital director Roh Sung-il visited Hwang at the hospital but remained silent to reporters.

Meanwhile, an elementary school student sent Hwang a card on his 53rd birthday.