Philip Morris International Inc. called off a sale or separation of its $1 billion US cigar business, citing the “current environment” in the latest deal to go awry amid market turmoil.

Readers respond to Dhruv Khullar’s essay on the Trump Adminstration’s threat to scientific progress and to Carrie Battan’s piece about Zyn.

An attempt to ban the beloved oral nicotine fix was quickly defeated after opposition from lobbying groups for the tobacco ...