As a #pulmpath pathologist I recieve consultant cases like that.
Wall of a pulmonary bulla with a squamous lesion but... TTF1 positive https://abs.twimg.com/emoji/v2/... draggable="false" alt="😳" title="Flushed face" aria-label="Emoji: Flushed face"> #pathtweetorial #ClonesTTF1

Remember that there are different clones of TTF1.
https://abs.twimg.com/emoji/v2/... draggable="false" alt="▶️" title="Right-pointing triangle" aria-label="Emoji: Right-pointing triangle"> We use 8G7G3/1 in #pulmpath (we recommend it also in our National Guidelines) https://twitter.com/lara_pijuan/status/1182950924928634880?s=21">https://twitter.com/lara_piju...
https://abs.twimg.com/emoji/v2/... draggable="false" alt="▶️" title="Right-pointing triangle" aria-label="Emoji: Right-pointing triangle"> But there are two more clones in the market: SP141 and SPT24 which can stain also squamous Cell carcinoma or others https://abs.twimg.com/emoji/v2/... draggable="false" alt="😬" title="Grimacing face" aria-label="Emoji: Grimacing face">

Here a great example of SPT24 staining a metastatic intestinal adenocarcinoma by @GeronimoJrLapac #clonesTTF1 https://twitter.com/geronimojrlapac/status/936689964645044225">https://twitter.com/geronimoj...

So going back to our case, my first question was asking for the TTF1 clone that they are using https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔍" title="Left-pointing magnifying glass" aria-label="Emoji: Left-pointing magnifying glass"> .....and mystery solved https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤓" title="Nerd face" aria-label="Emoji: Nerd face">

So remember to switch to 8G7G3/1 in #pulmpath as @smlungpathguy also recommend https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤓" title="Nerd face" aria-label="Emoji: Nerd face"> #TTF1 #ClonesTTF1 https://twitter.com/smlungpathguy/status/1224378423084298241">https://twitter.com/smlungpat...