It's also interesting to note which elite universities are not present as signatories. Notice that Caltech is missing. I'm curious about whether that is due to

It's also interesting to note which elite universities are not present as signatories. Notice that Caltech is missing. I'm curious about whether that is due to the significant funding they effectively receive as the managers of JPL and are concerned about retribution. It's indefensible IMO not to stand behind their community, many of whom are Iranian.