(Reuters) — Uber Technologies Inc’s Gary Marcus said he is stepping down from his post as head of AI Labs, four months after the unit was created.

Marcus, head of the recently launched AI Labs, said in a Facebook post on Wednesday that he is stepping down and will serve as a special advisor to AI Labs. The ride-hailing app had created AI Labs last year and also acquired Geometric Intelligence to form the initial AI Labs team.

Uber’s management practices have been called into question after a former employee had published a blog post last month describing a workplace where sexual harassment was common and remained unpunished, leading to an internal investigation.

Uber was not immediately available for comment.