Richard Ross, owner of Home, was a fairly important person in Lennon's
life.
When Ross became sick in the late 70s, Lennon (who had nominally
returned to Ono) was surprised to visit Ross at the same time May Pang
was present. Ross spoke to them both a bit, then he said: "It looks
like you two need some time alone. I'll visit the lobby for a bit."
It was also while out with Ross that Lennon met artist Alexa Grace. She
rebuffed Lennon's advances, saying "I'm not a groupie!" but Lennon never
forgot her, and reminisced about her in his diaries.
In Dakota Days, author John Green quotes Lennon as confessing to guilt
over not visiting a cancer-stricken friend of his who was in the
hospital. The friend was, I am convinced Ross, who succumbed to the
disease several years after Lennon's murder.