Five vignettes of Longinus are included in the Greek Sayings of the Desert Fathers. The third describes how a woman suffering from breast cancer was cured after an encounter with Longinus:

A woman had an illness they call cancer of the breast; she had heard of Abba Longinus and wanted to meet him. Now he lived at the ninth milestone from Alexandria [i.e., the Enaton]. As the woman was looking for him, the blessed man happened to be collecting wood beside the sea. When she met him, she said to him, “Abba, where does Abba Longinus, the servant of God live?” not knowing that it was he. He said, “Why are you looking for that old imposter? Do not go to see him, for he is a deceiver. What is the matter with you?” The woman showed him where she was suffering. He made the sign of the cross over the sore and sent her away saying, “Go, and God will heal you, for Longinus cannot help you at all.” The woman went away confident in this saying, and she was healed on the spot. Later, telling others what had happened and mentioning the distinctive marks of the old man, she learned that it was Abba Longinus himself.

Longinus (abbot) – Wikipedia

https://en.wikipedia.org/wiki/Longinus_(abbot)

Longinus (fl. 451–457) was the hegumenos (superior or abbot) of the Enaton, a monastic community outside Alexandria in Roman Egypt. He is the subject of a Sahidic Coptic hagiography, the Life of Saints Longinus and Lucius the Ascetics, and a Sahidic homily, In Honour of Longinus, by Bishop Basil of Oxyrhynchus.[1]