Next, we introduce a 3D molecule viewer which can be played on a Twitter timeline inlinely via our web server chemical.space . This feature is based on the Twitter Player Card system . The Player Card system is used as a video/audio player in the Twitter timeline, wherein the 3D molecule viewer works as interactive video content. This feature is currently available on web browsers, while the Twitter mobile application can not load Player Card directly in the timeline due to the limitation of Twitter's specifications. Users can view any Protein Data Bank (PDB) structures interactively without leaving their timeline on the browser. To embed the viewer in a tweet, users are expected to post a tweet containing a PDB ID string right after the bot's screen name with a #pdb hashtag (e.g., @souyakuchan 1ema #pdb).