I’ve been listening to @theblacklistgsm and there was a bit of back and forth about if this confirmed that Constantin Rostov is Liz’s father. When the episode aired and through the first couple of rewatches, I didn’t even question that Katarina was saying that Masha was safe because she’s female, therefore could not have the disease. Something about when they were talking about it struck me though - and really I partially blame Red for all of his comments about Kirk thinking that he’d found his long-lost daughter and never out-right confirming that Kirk is her father, even though he’s willing to confirm him as Constantin Rostov - but what if Masha was safe, not because the disease could never kill her, but because if she’d been born male and never developed it, Constantin might have questioned the child’s paternity?