Software, while beneficial, poses potential cybersecurity risks due to inherent vulnerabilities. Detecting these vulnerabilities is crucial, and deep learning has shown promise as an effective tool for this task due to its ability to perform well without extensive feature engineering. However, a challenge in deploying deep learning for vulnerability detection is the limited availability of training data. Recent research highlights the deep learning efficacy in diverse tasks. This success is attributed to instruction fine-tuning, a technique that remains under-explored in the context of vulnerability detection. This paper investigates the capability of models, specifically a recent language model, to generalize beyond the programming languages used in their training data. It also examines the role of natural language instructions in enhancing this generalization. Our study evaluates the model performance on a real-world dataset to predict vulnerable code. We present key insights and lessons learned, contributing to understanding the deep learning application in software vulnerability detection.