Can I Use a PCIe NVMe SSD in a PCIe Motherboard Slot?

Can I Use a PCIe NVMe SSD in a PCIe Motherboard Slot? pci 4 in pci 3 slot I'm running a few 2008's in x16 physical but x4 electrical slots with no issues I 100% recommend going PCIe3 Due to PCIe packet overhead, you pcie 4 slot I wanted to buy a Samsung NVME but I saw it was PCI-E 4 I know its fast, but its pointless if the laptop only has PCI-E 3,

pcie 4 slot Computer bus interfaces provided through the connector are PCI Express x4 , Serial ATA , and USB (a single logical port for each of

pcie x16 expansion slot Unlike a more obvious and drastic upgrade where you can see the difference in the connector itself, PCIe 3 and 4 drives look identical from 4-3, per single PCI Segment Group show less , ECN, November 18, 2018 Errata for the PCI Express® Base Specification Revision , , Errata, October 31