The episode was previously titled "Secrets and Lies."
Lena mentioned a "penicillin moment." Alexander Fleming discovered penicillin by accident, or serendipity, when he got back from vacation and realized that there was mold growing on unwashed laboratory equipment. Penicillin is an antibiotic, it is used to treat bacterial infections, as oppose to viral infections. (Virus are a lot smaller and tend to have the ability to hijack "cellular machinery" to reproduce uncontrollably.)
The episode title refers to the song Suspicious Minds, written and originally recorded by Mark James in 1968, and popularized by Elvis Presley a year later.