Sergei Millian met with Michael Cohen in Trump Tower in 2007, and had offered to connect Cohen with "some important people in Russia who could provide some assistance" for Trump's plans to build a skyscraper in Moscow.
Possibly, because Millian has said that when he told RIA journalists in April 2016 that he had met with Cohen at Trump Tower in 2007, that that's when Glenn Simpson had first started targeting him.
MT @SergeiMillian: "During Trump inauguration in January 2017, there was an attempt to poison me in Mayflower hotel where I stayed. Very few people know this. Now you know it, too."
"I don't know for sure who did it. It was an Avian [sic] water bottle drink that somebody placed for me"
"In case this incident ever gets looked into, the drink was placed on a hotel service tray outside my hotel suite"
"[Halper] also related that when [Page] had heard that [Halper] had recently been in Dubai, [Page] mentioned that he was in Abu Dhabi around the same time as [Halper]."
"The team asked [Halper] if he recalled when [Page] said he was in Abu Dhabi for Gazprom. [Halper] said that he believes it was approximately three months ago."
(Page told Schiff he was in Dubai on April 27, 2016)
Since Page was reported to have been in the UAE during the campaign season for Gazprom-related activities, then it probably stands to reason that Yatsenko is going to be dragged into this somehow.
"[Page] also said that in mid-October 2016, while crossing a street in New York City, his cell phone fell out of his pocket and was smashed by a car, resulting in a loss of encrypted communications."